Hermia Mount was about to get the sack.

This had never happened to her before. She was bright and conscientious, and her employers had always regarded her as a treasure, despite her sharp tongue. But her current boss, Herbert Woodie, was going to tell her she was fired, as soon as he worked up the courage.

Two Danes working for MI6 had been arrested at Kastrup aerodrome. They were now in custody and undoubtedly being interrogated. It was a bad blow to the Nightwatchmen network. Woodie was a peacetime MI6 man, a long-serving bureaucrat. He needed someone to blame, and Hermia was a suitable candidate.

Hermia understood this. She had worked for the British civil service for a decade, and she knew its ways. If Woodie were forced to accept that the blame lay with his department, he would pin it on the most junior person available. Woodie had never been comfortable working with a woman anyway, and he would be happy to see her replaced by a man.

At first Hermia was inclined to offer herself up as the sacrificial victim. She had never met the two aircraft mechanics - they had been recruited by Poul Kirke - but the network was her creation and she was responsible for the fate of the arrested men. She was as upset as if they had already died, and she did not want to go on.

After all, she thought, how much had she actually done to help the war effort? She was just accumulating information. None of it had ever been used. Men were risking their lives to send her photographs of Copenhagen harbor with nothing much happening. It seemed foolish.

But in fact she knew the importance of this laborious routine work. At some future date, a reconnaissance plane would photograph the harbor full of ships, and military planners would need to know whether this represented normal traffic or the sudden buildup of an invasion force - and at that point Hermia's photographs would become crucial.

Furthermore, the visit of Digby Hoare had given an immediate urgency to her work. The Germans' aircraft detection system could be the weapon that would win the war. The more she thought about it, the more likely it seemed that the key to the problem could lie in Denmark. The Danish west coast seemed the ideal location for a warning station designed to detect bombers approaching Germany.

And there was no one else in MI6 who had her ground-level knowledge of Denmark. She knew Poul Kirke personally and he trusted her. It could be disastrous if a stranger took over. She had to keep her job. And that meant outwitting her boss.

"This is bad news," Woodie said sententiously as she stood in front of his desk.

His office was a bedroom in the old house of Bletchley Park. Flowered wallpaper and silk-shaded wall lights suggested it had been occupied by a lady before the war. Now it had filing cabinets instead of wardrobes full of dresses, and a steel map table where once there might have been a dressing table with spindly legs and a triple mirror. And instead of a glamorous woman in a priceless silk negligee, the room was occupied by a small, self-important man in a gray suit and glasses.

Hermia faked the appearance of calm. "There's always danger when an operative is interrogated, of course," she said. "However - " She thought of the two brave men being interrogated and tortured, and her breath caught in her throat for a moment. Then she recovered. "However, in this case I feel the risk is slight."

Woodie grunted skeptically. "We may need to set up an inquiry."

Her heart sank. An inquiry meant an investigator from outside the department. He would have to come up with a scapegoat, and she was the obvious choice. She began the defense she had prepared. "The two men arrested don't have any secrets to betray," she said. "They were ground crew at the aerodrome. One of the Nightwatchmen would give them papers to be smuggled out, and they would stow the contraband in a hollow wheel chock." Even so, she knew, they might reveal apparently innocent details about how they were recruited and run, details which a clever spycatcher could use to track down other agents.

"Who passed them the papers?"

"Matthies Hertz, a lieutenant in the army. He's gone into hiding. And the mechanics don't know anyone else in the network."

"So our tight security has limited the damage to the organization."

Hermia guessed that Woodie was rehearsing a line he might speak to his superiors, and she forced herself to flatter him. "Exactly, sir, that's a good way of putting it."

"But how did the Danish police get to your people in the first place?"

Hermia had anticipated this question, and her answer was carefully prepared. "I think the problem is at the Swedish end."

"Ah." Woodie brightened. Sweden, being a neutral country, was not under his control. He would welcome the chance of shifting the blame to another department. "Take a seat, Miss Mount."

"Thank you." Hermia felt encouraged: Woodie was reacting as she had hoped. She crossed her legs and went on, "I think the Swedish go-between has been passing copies of the illegal newspapers to Reuters in Stockholm, and this may have alerted the Germans. You have always had a strict rule that our agents stick to information gathering, and avoid ancillary activities such as propaganda work." This was more flattery: she had never heard Woodie say any such thing, though it was a general rule in espionage.

However, he nodded sagely. "Indeed."

"I reminded the Swedes of your ruling as soon as I found out what was happening, but I fear the damage had been done."

Woodie looked thoughtful. He would be happy if he could claim that his advice had been ignored. He did not really like people to do as he suggested, because when things went well they just took the credit themselves. He preferred it if they ignored his counsel and things went wrong. Then he could say, "I told you so."

Hermia said, "Shall I do you a memo, mentioning your rule and quoting my signal to the Swedish Legation?"

"Good idea." Woodie liked this even better. He would not be allocating blame himself, merely quoting an underling who would incidentally be giving him credit for sounding the alarm.

"Then we'll need a new way of getting information out of Denmark. We can't use radio for this kind of material, it takes too long to broadcast."

Woodie had no idea how to organize an alternative smuggling route. "Ah, that's a problem," he said with a touch of panic.

"Fortunately we have set up a fallback option, using the boat train that crosses from Elsinore in Denmark to Helsingborg in Sweden."

Woodie was relieved. "Splendid," he said.

"Perhaps I should say in my memo that you've authorized me to action that."

"Fine."

She hesitated. "And . . . the inquiry?"

"You know, I'm not sure that will be necessary. Your memo should serve to answer any questions."

She concealed her relief. She was not going to be fired after all.

She knew she should quit while she was ahead. But there was another problem she was desperate to raise with him. This seemed like an ideal opportunity. "There is one thing we could do that would improve our security enormously, sir."

"Indeed?" Woodie's expression said that if there were such a procedure he would already have thought of it.

"We could use more sophisticated codes."

"What's wrong with our poem and book codes? Agents of MI6 have been using them for years."

"I fear the Germans may have figured out how to break them."

Woodie smiled knowingly. "I don't think so, my dear."

Hermia decided to take the risk of contradicting him. "May I show you what I mean?" Without waiting for his answer, she went on, "Take a look at this coded message." She quickly scribbled on her pad:

gsff cffs jo uif dbouffo

She said, "The commonest letter is f."

"Obviously."

"In the English language, the letter used most commonly is e, so the first thing a code-breaker would do is assume that f stands for e, which gives you this."

gsEE cEEs jo uiE dbouEEo

"It could still mean anything," Woodie said.

"Not quite. How many four-letter words are there ending in double e?"

"I'm sure I've no idea."

"Only a few common ones: flee, free, glee, thee, and tree. Now look at the second group."

"Miss Mount, I don't really have time - "

"Just another few seconds, sir. There are many four-letter words with a double e in the middle. What could the first letter be? Not a, certainly, but it could be b. So think of words beginning bee that might logically come next. Flee been makes no sense, free bees sounds odd, although tree bees might be right - "

Woodie interrupted. "Free beer!" he said triumphantly.

"Let's try that. The next group is two letters, and there aren't many two-letter words: an, at, in, if, it, on, of, or, and up are the commonest. The fourth group is a three-letter word ending in e, of which there are many, but the commonest is the."

Woodie was getting interested despite himself. "Free beer at the something."

"Or in the something. And that something is a seven-letter word with a double e in it, so it ends eed, eef, eek, eel, eem, een, eep - "

"Free beer in the canteen!" said Woodie triumphantly.

"Yes," Hermia said. She sat in silence, looking at Woodie, letting the implications of what had just happened sink in. After a few moments she said, "That's how easy our codes are to break, sir." She looked at her watch. "It took you three minutes."

He grunted. "A good party trick, Miss Mount, but the old hands at MI6 know more about this sort of thing than you, take it from me."

It was no good, she thought despairingly. He would not be moved on this today. She would have to try again later. She forced herself to give in gracefully. "Very good, sir."

"Concentrate on your own responsibilities. What are the rest of your Nightwatchmen up to?"

"I'm about to ask them to keep their eyes open for any indications that the Germans have developed long-distance aircraft detection."

"Good lord, don't do that!"

"Why not?"

"If the enemy finds out we're asking that question, he'll guess we've got it!"

"But, sir - what if he does have it?"

"He doesn't. You can rest assured."

"The gentleman who came here from Downing Street last week seemed to think otherwise."

"In strict confidence, Miss Mount, an MI6 committee looked into the whole radar question quite recently, and concluded that it would be another eighteen months before the enemy developed such a system."

So, Hermia thought, it was called radar. She smiled. "That's so reassuring," she lied. "I expect you were on the committee yourself, sir?"

Woodie nodded. "In fact I chaired it."

"Thank you for setting my mind at rest. I'll get on with that memo."

"Jolly good."

Hermia went out. Her face ached with smiling and she was exhausted by the effort of constantly deferring to Woodie. She had saved her job, and she permitted herself a moment of satisfaction as she walked back to her own office. But she had failed with the codes. She had found out the name of the long-distance aircraft detection system - radar - but it was clear Woodie would not let her investigate whether the Germans had such a system in Denmark.

She longed to do something of immediate value to the war effort. All this routine work made her impatient and frustrated. It would be so satisfying to see some real results. And it might even justify what had happened to those two poor aircraft mechanics at Kastrup.

She could investigate enemy radar without Woodie's permission, of course. He might find out, but she was willing to take that risk. However, she did not know what to tell her Nightwatchmen. What should they be looking for, and where? She needed more information before she could brief Poul Kirke. And Woodie was not going to give it to her.

But he was not her only hope.

She sat down at her desk, picked up the phone, and said, "Please connect me with Number Ten, Downing Street."

She met Digby Hoare in Trafalgar Square. She stood at the foot of Nelson's Column and watched him cross the road from Whitehall. She smiled at the energetic, lopsided stride that already seemed to her characteristic of him. They shook hands, then walked toward Soho.

It was a warm summer evening, and the West End of London was busy, its pavements thronged with people heading for theaters, cinemas, bars, and restaurants. The happy scene was marred only by bomb damage, the occasional blackened ruin in a row of buildings standing out like a rotten tooth in a smile.

She had thought they were going for a drink in a pub, but Digby led her to a small French restaurant. The tables either side of them were empty, so they could talk without being overheard.

Digby was wearing the same dark gray suit, but this evening he had on a light blue shirt that set off his blue eyes. Hermia was pleased she had decided to wear her favorite piece of jewelry, a panther brooch with emerald eyes.

She was keen to get down to business. She had refused to go on a date with Digby and she did not want him to get the idea that she might have changed her mind. As soon as they had ordered, she said, "I want to use my agents in Denmark to find out whether the Germans have radar."

He looked at her through narrowed eyes. "The question is more complicated than that. It's now beyond doubt that they have radar, as we do. But theirs is more effective than ours - devastatingly so."

"Oh." She was taken aback. "Woodie told me . . . Never mind."

"We're desperate to find out why their system is so good. Either they have invented something better than we've got, or they've devised a way of using it more effectively - or both."

"All right." She rapidly readjusted her ideas in the light of this new information. "Just the same, it seems likely that some of this machinery is in Denmark."

"It would be a logical place - and the code name 'Freya' suggests Scandinavia."

"So what are my people looking for?"

"That's difficult." He frowned. "We don't know what their machinery looks like - that's the point, isn't it?"

"I presume it gives out radio waves."

"Yes, of course."

"And presumably the signals travel a good distance - otherwise the warning wouldn't be early enough."

"Yes. It would be useless unless the signals traveled at least, say, fifty miles. Probably more."

"Could we listen for them?"

He raised his eyebrows in surprise. "Yes, with a radio receiver. Clever notion - I don't know why no one else thought of it."

"Can the signals be distinguished from other transmissions, such as normal broadcasts, the news and so on?"

He nodded. "You'd be listening for a series of pulses, probably very rapid, say a thousand per second. You'd hear it as a continuous musical note. So you'd know it wasn't the BBC. And it would be quite different from the dots and dashes of military traffic."

"You're an engineer. Could you put together a radio receiver suitable for picking up such signals?"

He looked thoughtful. "It's got to be portable, presumably."

"It should pack into a suitcase."

"And work off a battery, so it can be used anywhere."

"Yes."

"It might be possible. There's a team of boffins in Welwyn who do this stuff all day." Welwyn was a small town between Bletchley and London. "Exploding turnips, radio transmitters concealed in bricks, that sort of thing. They could probably cobble something together."

Their food came. Hermia had ordered a tomato salad. It came with a sprinkling of chopped onion and a sprig of mint, and she wondered why British cooks could not produce food that was simple and delicious like this, instead of tinned sardines and boiled cabbage.

"What made you set up the Nightwatchmen?" Digby asked her.

She was not sure what he meant. "It seemed like a good idea."

"Still, not an idea that would occur to the average young woman, if I may say so."

She thought back, remembering the struggle she had had with another bureaucratic boss, and asked herself why she had persisted. "I wanted to strike a blow against the Nazis. There's something about them that I find absolutely loathsome."

"Fascism blames problems on a false cause - people of other races."

"I know, but it's not that. It's the uniforms, the strutting and posturing, and the way they howl out those hateful speeches. It just makes me sick."

"When did you experience all this? There aren't many Nazis in Denmark."

"I spent a year in Berlin in the thirties. I watched them marching and saluting and spitting on people and smashing the windows of Jewish shopkeepers. I remember thinking: These people have to be stopped before they spoil the whole world. I still think so. I'm more sure of that than anything."

He smiled. "Me, too."

Hermia had a seafood fricassee, and once again she was struck by what a French cook could do with common ingredients, despite rationing. The dish contained sliced eel, some of the winkles beloved of Londoners, and flaked cod, but it was all fresh and well seasoned, and she tucked in with relish.

Every now and again she caught Digby's eye, and he always had the same look, a mixture of adoration and lust. It alarmed her. If he fell in love with her, it could only lead to trouble and heartbreak. But it was pleasing, as well as embarrassing, to have a man so obviously desire her. At one point she felt herself flush, and put her hand to her throat to hide her blushes.

She deliberately turned her thoughts to Arne. The first time she talked to him, in the bar of a ski hotel in Norway, she knew she had found what was missing in her life. "Now I understand why I've never had a satisfactory relationship with a man," she had written to her mother. "It's because I hadn't met Arne." When he proposed to her, she had said, "If I'd known there were men like you, I'd have married one years ago."

She said yes to everything he suggested. She was normally so intent on having her own way that she had never been able to share an apartment with a girlfriend, but with Arne she lost her willpower. Every time he asked her to go out with him she accepted; when he kissed her, she kissed him back; when he stroked her breasts under her ski sweater she just sighed with pleasure; and when he knocked on the door of her hotel room at midnight she said: "I'm so glad you're here."

Thinking of Arne helped her to feel cooler toward Digby, and as they finished their meal she turned the conversation to the war. An Allied army including British, Commonwealth, and Free French forces had invaded Syria. It was a skirmish on the far fringes, and they both found it hard to see the outcome as important. The conflict in Europe was all that really counted. And here it was a war of bombers.

When they left the restaurant it was dark, but there was a full moon. They walked south, heading for her mother's house in Pimlico, where Hermia was going to spend the night. As they were crossing St. James's Park the moon went behind a cloud, and Digby turned to her and kissed her.

She could not help admiring the swift sureness of his moves. His lips were on hers before she could turn away. With a strong hand he pulled her body to his, and her breasts pressed against his chest. She knew she should be indignant, but to her consternation she found herself responding. She suddenly remembered what it was like to feel a man's hard body and hot skin, and in a rush of desire she opened her mouth to him.

They kissed hungrily for a minute, then his hand went to her breast, and that broke the spell. She was too old and respectable to be groped in a park. She broke the clinch.

The thought of taking him home crossed her mind. She imagined the pained disapproval of Mags and Bets, and the picture made her laugh.

"What is it?" he said.

She saw that he looked hurt. He probably imagined her laughter had to do with his disability. I must remember how vulnerable he is to mockery, she thought. She hastened to explain. "My mother is a widow who lives with a middle-aged spinster. I just thought how they would react if I told them I wanted to bring a man home for the night."

The hurt look went away. "I like your thinking," he said, and he tried to kiss her again.

She was tempted, but thought of Arne, and put a resisting hand on Digby's chest. "No more," she said firmly. "Walk me home."

They left the park. The momentary euphoria faded, and she began to feel troubled. How could she enjoy kissing Digby when she loved Arne? As they passed Big Ben and Westminster Abbey, an air-raid warning put all such thoughts out of her mind.

Digby said, "Do you want to find a shelter?"

Many Londoners no longer took cover during air raids. Fed up with sleepless nights, some had decided it was worth risking the bombs. Others had become fatalistic, saying that a bomb either had your number on it or not, and there was nothing you could do either way. Hermia was not quite so blase, but on the other hand she had no intention of spending the night in an air-raid shelter with the amorous Digby. She nervously twisted the engagement ring on her left hand. "We're only a few minutes away," she replied. "Do you mind if we keep going?"

"I may be forced to spend the night at your mother's house after all."

"At least I'll be chaperoned."

They hurried through Westminster into Pimlico. Searchlights probed the scattered clouds, then they heard the sinister low drone of heavy aircraft, like a large beast growling hungrily, deep in its throat. An antiaircraft gun boomed somewhere, and flak burst in the sky like fireworks. Hermia wondered whether her mother was out driving her ambulance tonight.

To Hermia's horror, bombs started to fall nearby, although it was normally the industrial East End that was hardest hit. There was a deafening crump that seemed to come from the next street. A minute later, a fire engine roared by. Hermia walked on as fast as she could.

Digby said, "You're so cool - aren't you scared?"

"Of course I'm scared," she said impatiently. "I'm just not panicking."

They turned a corner and saw a blazing building. The fire engine was outside and the men were unrolling hoses.

"How much farther?" Digby asked.

"Next street," Hermia said, panting.

When they rounded the next corner, they saw another fire engine at the far end of the street, near Mags's house. "Oh, God," Hermia said, and she broke into a run. Her heart pounded with fear as she dashed along the pavement. There was an ambulance, she saw, and at least one house in her mother's section had been hit. "No, please," she said aloud.

Coming closer, she was perplexed that she could not identify her mother's house, though she saw clearly that the house next door was on fire. She stopped and stared, trying to understand what she was looking at. Then, at last, she realized that her mother's house was gone. Nothing was left of it but a gap in the terrace and a pile of debris. She groaned in despair.

Digby said, "Is that the house?"

Hermia nodded, unable to speak.

Digby called to a fireman in an authoritative voice. "You!" he said. "Any sign of the occupants of this building?"

"Yes, sir," said the fireman. "One person was blown clear by the blast." He pointed to the small front yard of the undamaged house on the far side. There was a body on a stretcher lying on the ground. The face was covered.

Hermia felt Digby take her arm. Together they entered the yard.

Hermia knelt down and Digby uncovered the face.

"It's Bets," Hermia said, with a sickeningly guilty feeling of relief.

Digby was looking around. "Who's that, sitting on the wall?"

Hermia looked up, and her heart lurched as she recognized the figure of her mother, dressed in her ambulance uniform and tin hat, slumped on the low wall as if all the life had gone out of her. "Mother?" she said.

Her mother looked up, and Hermia saw that tears were streaming down her face.

Hermia went to her and put her arms around her.

"Bets is dead," her mother said.

"I'm sorry, Mother."

"She loved me so much," her mother sobbed.

"I know."

"Do you? Do you know? She waited all her life for me. Did you realize that? All her life."

Hermia hugged her mother hard. "I'm so sorry," she said.

There had been about two hundred Danish ships at sea on the morning of April 9, 1940, when Hitler invaded Denmark. All that day, Danish-language broadcasts by the BBC appealed to sailors to head for Allied ports rather than return home to a conquered country. In total, about five thousand men accepted the offer of refuge. Most sought harbor on the east coast of England, hoisted the Union Jack, and continued to sail throughout the war under the British flag. Consequently, by the middle of the following year small communities of Danes had settled in several English ports.

Hermia decided to go to the fishing town of Stokeby. She had visited the place twice previously to talk to the Danes there. On this occasion she told her boss, Herbert Woodie, that her mission was to check her somewhat out-of-date plans of the main Danish ports and make any alterations necessary.

He believed her.

She had a different story for Digby Hoare.

Digby came to Bletchley, two days after the bomb destroyed her mother's house, with a radio receiver and direction finder neatly packed into a used-looking tan leather suitcase. As he showed her how to use the equipment, she thought guiltily of the kiss in the park, and how much she had enjoyed it, and wondered uneasily how she would be able to look Arne in the eye.

Her original plan had been to attempt to smuggle the radio receiver to the Nightwatchmen, but she had since thought of something simpler. The signals from the radar apparatus could probably be picked up at sea just as easily as on land. She told Digby she was going to pass the suitcase to the captain of a fishing boat and teach him how to use it. Digby approved.

That plan might well have worked, but in truth she did not want to hand such an important job over to someone else. So she intended to go herself.

In the North Sea, between England and Denmark, there was a large sandbank known as Dogger Bank, where the sea was as shallow as fifty feet in places, and the fishing was good. Both British and Danish ships trawled there. Strictly speaking, Denmark-based vessels were banned from venturing so far from their coast, but Germany needed herrings, so the ban was irregularly enforced and constantly defied. For some time, Hermia had had it in the back of her mind that messages - or even people - might travel between the two countries on fishing boats, transferring from Danish to British or vice versa in the middle. Now, however, she had a better idea. The far end of the Dogger Bank was only a hundred miles from the Danish coast. If all her guesswork turned out to be right, the signals from the Freya machine should be detectable from the fishing ground.

She took a train on Friday afternoon. She was dressed for the sea in trousers, boots, and a loose sweater, with her hair pushed under a man's checked cap. As the train rolled through the flat fen country of eastern England, she worried whether her plan would work. Would she find a ship willing to take her? Would she pick up the signals she was expecting? Or was the whole thing a waste of time?

After a while her mind turned to her mother. Mags had been under control again yesterday at Bets's funeral, appearing calmly sorrowful rather than stricken by grief, and today she had gone to Cornwall to stay with her sister, Hermia's aunt Bella. But on the night of the bomb her soul had been laid bare.

The two women had been devoted friends, but it was clearly more than that. Hermia did not really want to think what else could be involved, but she could not help being intrigued. Setting aside the embarrassing thought of what physical relation there might have been between Mags and Bets, Hermia was shocked that her mother had nourished a passionate lifelong attachment that had remained carefully disguised, all those years, from Hermia herself and presumably from Mags's husband, Hermia's father.

She arrived in Stokeby at eight o'clock on a mild summer evening and went from the railway station straight to the Shipwright's Arms pub on the dockside. It took her only a few minutes of asking around to learn that Sten Munch, a Danish captain she had met on her last visit here, was due to sail in the morning in his vessel Morganmand, which meant "early riser." She found Sten at his house on the hillside, clipping the hedge in his front garden like a born Englishman. He invited her in.

He was a widower and lived with his son, Lars, who had been on the boat with him on April 9, 1940. Lars had since married a local girl, Carol. When Hermia went inside, Carol was nursing a tiny baby a few days old. Lars made tea. They all spoke English for Carol's sake.

Hermia explained that she needed to get as close as possible to the Danish coast in an attempt to listen to a German wireless transmission - she did not say what kind. Sten did not question her story. "Of course!" he said expansively. "Anything to help defeat the Nazis! But my boat is not really suitable."

"Why not?"

"It's very small - only thirty-five feet - and we'll be away for about three days."

Hermia had been expecting this. She had told Woodie she needed to get her mother settled in new accommodation and would be back sometime next week. "That's all right," she told Sten. "I've got time."

"My boat has only three berths. We sleep in shifts. It's not designed for ladies. You should go in a larger vessel."

"Is there one leaving in the morning?"

Sten looked at Lars, who said, "No. Three set off yesterday, won't return until next week. Peter Gorning should be back tomorrow. He'll go out again about Wednesday."

She shook her head. "Too late."

Carol looked up from her baby. "They sleep in their clothes, you know. That's why they stink when they get home. It's worse than the smell of the fish."

Hermia immediately liked her for her down-to-earth directness. "I'll be fine," she said. "I can sleep in my clothes, in a bed still warm from the previous occupant. It won't kill me."

Sten said, "You know I want to help. But the sea is not for women. You were made for the gracious things in life."

Carol snorted scornfully. "Like giving birth?"

Hermia smiled, grateful to have Carol as an ally. "Exactly. We can put up with discomfort."

Carol nodded vigorously. "Think of what Charlie's going through in the desert." She explained to Hermia, "My brother Charlie's in the army somewhere in North Africa."

Sten looked cornered. He did not want to take Hermia, but he was reluctant to say so, wanting to appear patriotic and brave. "We leave at three o'clock in the morning."

"I'll be there."

Carol said, "You might as well stay here, now. We've got a spare room." She looked at her father-in-law. "If that's all right with you, Pa."

He had run out of excuses. "Of course!" he said.

"Thank you," said Hermia. "You're very kind."

They went to bed early. Hermia did not undress, but sat up in her room with the light on. She was afraid that if she overslept, Sten would leave without her. The Munch family were not great readers, and the only book she could find was the Bible in Danish, but it kept her awake. At two o'clock she went to the bathroom and washed quickly, then tiptoed downstairs and put the kettle on. Sten appeared at half past two. When he saw Hermia in the kitchen he looked surprised and disappointed. She poured tea into a big cup and he took it gratefully enough.

Hermia, Sten, and Lars walked down the hill to the quay a few minutes before three o'clock. Two more Danish men were waiting at the dockside. The Morganmand was very small. Thirty-five feet was about the length of a London bus. The vessel was made of wood, and had one mast and a diesel engine. On deck was a small wheelhouse and a series of hatches over the hold. From the wheelhouse, a companionway led down to the living quarters. At the stern end were the massive spars and the winding gear for the nets.

Dawn was breaking as the little vessel threaded its way through the defensive minefield at the mouth of the harbor. The weather was fine, but they encountered a swell of five or six feet as soon as they left the shelter of the land. Fortunately, Hermia was never seasick.

Throughout the day, she tried to make herself useful around the boat. She knew no seamanship, so she kept the galley clean. The men were used to preparing food for themselves, but she washed their dishes and the frying pan in which they cooked almost everything they ate. She made sure she talked to the two crewmen, speaking Danish, getting on terms of respectful friendliness with each of them. When she had nothing else to do, she sat on the deck and enjoyed the sunshine.

Toward midday they reached the Outer Silver Pit, on the southeast corner of the Dogger Bank, and began to trawl. The boat reduced speed and headed northeast. At first they could not find the fish, and the nets came up almost empty. Then, toward the end of the afternoon, the fish started running.

At nightfall, Hermia went below and lay on a bunk. She thought she would not sleep, but she had been up for thirty-six hours, and tiredness got the better of tension. She dropped off within minutes.

During the night she was awakened, briefly, by the volcanic rumble of a flight of bombers overhead. She wondered vaguely whether it was the RAF heading for Germany or the Luftwaffe going the other way, then drifted off to sleep again.

The next thing she knew, Lars was shaking her. "We're approaching our nearest point to Denmark," he said. "We're about a hundred and twenty miles off Morlunde."

Hermia took her suitcase receiver up on deck. It was already full daylight. The men were hauling in a net full of flapping fish, mainly herrings and mackerel, and tipping them into the hold. Hermia found it a gruesome sight, and looked away.

She connected the battery to the radio and was relieved to see the dials flicker. She fixed the aerial to the mast with a length of wire thoughtfully provided by Digby. She let the set warm up, then put on the headphones.

As the boat motored northeast, Hermia roamed up and down the wireless frequencies. As well as the BBC's broadcasts in English, she picked up French, Dutch, German, and Danish radio programs, plus a host of Morse transmissions which she presumed were military signals from both sides. At the first pass up and down, she heard nothing that might have been radar.

She repeated the exercise more slowly, making sure she missed nothing. She had plenty of time. But once again she did not hear what she was listening for.

She kept trying.

After two hours she noticed that the men had stopped fishing and were watching her. She caught the eye of Lars, who said, "Any luck?"

She pulled off the headphones. "I'm not picking up the signal I was expecting," she said in Danish.

Sten replied in the same language. "The fish were running all night. We've done well - our hold is full. We're ready to go home."

"Would you motor north for a while? I must try to find this signal - it's really important."

Sten looked doubtful, but his son said, "We can afford it, we've had a good night."

Sten was reluctant. "What if a German spotter plane flies overhead?"

Hermia said, "You could throw out nets and pretend to be fishing."

"There are no fishing grounds where you want to go."

"German pilots don't know that."

One of the crew put in, "If it's to help free Denmark . . ."

The other hand nodded vigorously.

Once again, Hermia was saved by Sten's reluctance to appear cowardly in front of others. "All right," he said. "We'll head north."

"Keep a hundred miles off the coast," Hermia said as she put the headphones back on.

She continued to scan the frequencies. As time went by, she became less hopeful. The likeliest place for a radar station was at the southern end of Denmark's coast, near the border with Germany. She had thought she would pick up the broadcast early. But her hopes fell by the hour as the boat headed north.

She was not willing to leave the set alone for more than a minute or two, so the fishermen brought her tea at intervals, and a bowl of canned stew at suppertime. While listening, she gazed east. She could not see Denmark, but she knew Arne was there somewhere, and she enjoyed feeling closer to him.

Toward nightfall, Sten knelt on the deck beside her to talk, and she took off the headphones. "We're off the northern point of the Jutland peninsula," he said. "We have to turn back."

In desperation she said, "Could we go closer? Maybe a hundred miles offshore is too far away to pick up the signal."

"We need to head for home."

"Could we follow the coast southward, retracing our course, but fifty miles closer to land?"

"Too dangerous."

"It's almost dark. There are no spotter planes at night."

"I don't like it."

"Please. It's very important." She shot an appealing look at Lars, who was standing nearby, listening. He was bolder than his father, perhaps because he saw his future in Britain, with his English wife.

As she was hoping, Lars joined in. "How about seventy-five miles offshore?"

"That would be great."

Lars looked at his father. "We have to go south anyway. It won't add more than a few hours to our voyage."

Sten said angrily, "We'll be putting our crew in danger!"

Lars replied mildly, "Think of Carol's brother in Africa. He's put himself in danger. This is our chance to do something to help."

"All right, you take the wheel," Sten said sulkily. "I'm going to sleep." He stepped into the wheelhouse and flung himself down the companionway.

Hermia smiled at Lars. "Thanks."

"We should thank you."

Lars turned the boat around and Hermia continued to scan the airwaves. Night fell. They sailed without lights, but the sky was clear and there was a three-quarter moon, which made Hermia feel that the boat must be conspicuous. However, they saw no aircraft and no other shipping. Periodically, Lars checked their position with a sextant.

Her mind drifted back to the air raid she and Digby had been in a few days ago. It was the first time she had been caught out of doors during a raid. She had managed to remain calm, but it had been a terrifying scene: the drone of the aircraft, the searchlights and the flak, the crump of falling bombs and the hellish light of burning houses. Yet here she was doing her best to help the RAF inflict the same horrors on German families. It seemed mad - but the only alternative was to let the Nazis take over the world.

It was a short midsummer night, and dawn broke early. The sea was unusually calm. A morning mist rose from the surface, reducing visibility and making Hermia feel safer. As the boat continued south, she became more anxious. She must pick up the signal soon - unless she and Digby were wrong, and Herbert Woodie right.

Sten came on deck with a mug of tea in one hand and a bacon sandwich in the other. "Well?" he said. "Have you got what you wanted?"

"It's most likely to come from the south of Denmark," she said.

"Or nowhere at all."

She nodded despondently. "I'm beginning to think you're right." Then she heard something. "Wait!" She had been scanning upward through the frequencies, and thought she had heard a musical note. She reversed the knob and went down, searching for the spot. She got a lot of static, then the note again - a pure machine-like tone about an octave above middle C. "I think this could be it!" she said joyfully. The wavelength was 2.4 meters. She made a note in the little book Digby had tucked into the suitcase.

Now she had to determine the direction. Incorporated into the receiver was a dial graduated from one to 360 with a needle pointing to the source of the signal. Digby had emphasized that the dial had to be aligned precisely with the center line of the boat. Then the direction of the signal could be calculated from the heading of the boat and the needle on the dial. "Lars!" she called. "What's our heading?"

"East-southeast," he said.

"No, exactly."

"Well . . ." Although the weather was fine and the sea was calm, nevertheless the boat was moving all the time, and the compass was never still.

"As best you can," she said.

"One hundred and twenty degrees."

The needle on her dial pointed to 340. Adding 120 to that brought the direction around to 100. Hermia made a note. "And what is our position?"

"Wait a minute. When I shot the stars, we were crossing the fifty-sixth parallel." He looked at the log, checked his wristwatch, and called out their latitude and longitude. Hermia wrote down the numbers, knowing they were only an estimate.

Sten said, "Are you satisfied now? Can we go home?"

"I need another reading so that I can triangulate the source of the broadcast."

He grunted in disgust and walked away.

Lars winked at her.

She kept the receiver tuned to the note as they motored south. The needle on the direction finder moved imperceptibly. After half an hour she again asked Lars for the boat's heading.

"Still one-twenty."

The needle on her dial now pointed to 335. The direction of the signal was therefore 095. She asked him to estimate their position again, and wrote the numbers down.

"Home?" he said.

"Yes. And thank you."

He turned the wheel.

Hermia was triumphant, but she could not wait to find out where the signal was coming from. She went into the wheelhouse and found a large-scale chart. With Lars's help she marked the two positions she had noted and drew lines for the bearing of the signal from each position, correcting for True North. The lines intersected off the coast, near the island of Sande.

"My God," Hermia said. "That's where my fiance comes from."

"Sande? I know it - I went to watch the racing car speed trials there a few years back."

She was jubilant. Her guess had been right and her method had worked. The signal she had been expecting was coming from the most logical place.

Now she needed to send Poul Kirke, or one of his team, to Sande to look around. As soon as she returned to Bletchley she would send a coded message.

A few minutes later, she took another heading. The signal was weak now, but the third line on the map made a triangle with the other two, and the island of Sande lay mainly within that triangle. All the calculations were approximate, but the conclusion seemed clear. The radio signal was coming from the island.

She could hardly wait to tell Digby.