IT WA S A minute before three when Dieter parked outside the Hotel Frankfort.

He hurried across the cobbled square to the cathedral under the stony gaze of the carved angels in the buttresses.

It was almost too much to hope that an Allied agent would show up at the rendezvous the first day.

On the other hand, if the invasion really were imminent, the Allies would be throwing in every last asset.

He saw Mademoiselle Lemas's Simca Cinq parked to one side of the square, which meant that Stephanie was already here.

He was relieved to have arrived in time.

If anything should go wrong, he would not want her to have to deal with it alone.

He passed through the great west door into the cool gloom of the interior.

He looked for Hans Hesse and saw him sitting in the back row of pews.

They nodded briefly to one another but did not speak.

Right away Dieter felt like a violator.

The business he was engaged upon should not take place in this atmosphere.

He was not very devout-less so than the average German, he thought-but he was certainly no unbeliever.

He felt uncomfortable catching spies in a place that had been a holy sanctuary for hundreds of years.

He shook off the feeling as superstitious.

He crossed to the north side of the building and walked up the long north aisle, his footsteps ringing on the stone floor.

When he reached the transept, he saw the gate, railing, and steps leading down to the crypt, which was below the high altar.

Stephanie was down there, he assumed, wearing one black shoe and one brown.

From here he could see in both directions: back the way he had come the length of the north aisle, and forward around the curved ambulatory at the other end of the building.

He knelt down and folded his hands in prayer.

He said, "0 Lord, forgive me for the suffering I inflict on my prisoners.

You know I'm trying my best to do my duty.

And forgive me for my sin with Stephanie.

I know it's wrong, but You made her so lovely that I can't resist the temptation.

Watch over my dear Waltraud, and help her to care for Rudi and little Mausi, and protect them from the bombs of the RAE And be with Field Marshal Rommel when the invasion comes, and give him the power to push the Allied invaders back into the sea.

It's a short prayer to have so much in it, but You know that I have a lot to do right now.

Amen." He looked around.

There was no service going on, but a handful of people were scattered around the pews in the side chapels, praying or just sitting quietly in the sacred stillness.

A few tourists walked around the aisles, talking in hushed voices about the medieval architecture, bending their necks to peer up into the vastness of the vaulting.

If an Allied agent showed up today, Dieter planned simply to watch and make sure nothing went wrong.

Ideally he would not have to do anything.

Stephanie would talk to the agent, exchange passwords, and take him home to the rue du Bois.

After that, his plans were vaguer.

Somehow, the agent would lead him to others.

At some point, there would be a breakthrough: an unwise person would be found to have a written list of names and addresses; a wireless set and a code book would fall into Dieter's hands; or he would capture someone like Flick Clairet, who would, under torture, betray half the French Resistance.

He checked his watch.

It was five past three.

Probably no one would come today.

He looked up.

To his horror, he saw Will Weber.

What the hell was he doing here? Weber was in plain clothes, wearing his green tweed suit.

With him was a younger Gestapo man in a check jacket.

They were coming from the east end of the church, walking around the ambulatory toward Dieter, though they had not seen him.

They drew level with the crypt door and stopped.

Dieter cursed under his breath.

This could ruin everything.

He almost hoped that no British agent would come today.

Looking along the north aisle, he saw a young man carrying a small suitcase.

Dieter narrowed his eyes: most of the people in the church were older.

The man was wearing a shabby blue suit of French cut, but he looked like a Viking, with red hair, blue eyes, and pale pink skin.

It was a very English combination, but could also be German.

At first glance, the young man might be an officer in mufti, seeing the sights or even intending to pray.

However, his behavior gave him away.

He walked purposefully along the aisle, neither looking at the pillars like a tourist nor taking a seat like a worshiper.

Dieter's heart beat faster.

An agent on the first day! And the bag he carried was almost certainly a suitcase radio.

That meant he had a code book, too.

This was more than Dieter had dared to hope for.

But Weber was here to mess everything up.

The agent passed Dieter and slowed his walk, obviously looking for the crypt.

Weber saw the man, gave him a hard look, then turned and pretended to study the fluting on a column.

Maybe it was going to be all right, Dieter thought.

Weber had done a stupid thing in coming here, but perhaps he was just planning to observe.

Surely he was not such an imbecile as to interfere? He could ruin a unique opportunity.

The agent found the crypt gate and disappeared down the stone steps.

Weber looked across the north transept and gave a nod.

Following his gaze, Dieter saw two more Gestapo men lurking beneath the organ loft.

That was a bad sign.

Weber did not need four men just to observe.

Dieter wondered if he had time to speak to Weber, get him to call his men off But Weber would argue, and there would be a row, and then- As it turned out, there was no time.

Almost immediately, Stephanie came up from the crypt with the agent right behind her.

When she reached the top of the steps she saw Weber.

A look of shock came over her face.

She was disoriented by his unexpected presence, as if she had walked on stage and found herself in the wrong play.

She stumbled, and the young agent caught her elbow and steadied her.

She recovered her composure with characteristic speed and gave him a grateful smile.

Well done, my girl, Dieter thought.

Then Weber stepped forward.

"No!" Dieter said involuntarily.

No one heard him.

Weber took the agent by the arm and said something.

Dieter's heart sank as he realized Weber was making an arrest.

Stephanie backed away from the little tableau, looking bewildered.

Dieter got up and walked quickly toward the group.

He could only think that Weber had decided to grab the glory by capturing an agent.

It was insane but possible.

Before Dieter got close, the agent shook off Weber's hand and bolted.

Weber's young companion in the check jacket reacted fast.

He took two big strides after the agent, flung himself forward in a flying tackle, and threw his arms around the agent's knees.

The agent stumbled, but he was moving strongly, and the Gestapo man could not hold him.

The agent recovered his balance, straightened up, and ran on, still clutching his suitcase.

The sudden running steps, and the grunts made by both men, sounded loud in the hushed cathedral, and everyone looked.

The agent ran toward Dieter.

Dieter saw what was going to happen and groaned.

The second pair of Gestapo men stepped out of the north transept.

The agent saw them and seemed to guess what they were, for he swerved left, but he was too late.

One of the men stuck out a foot and tripped him.

He fell headlong, his chunky body hitting the stone floor with a thwack.

The suitcase went flying.

Both Gestapo men jumped on him.

Weber came running up, looking pleased.

"Shit," Dieter said aloud, forgetting where he was.

The mad fools were ruining everything.

Maybe he could still save the situation.

He reached into his jacket, drew his Walther P38, thumbed the safety catch, and pointed it at the Gestapo men who were holding the agent down.

Speaking French, he yelled at the top of his voice, "Get off him now, or I shoot!" Weber said, "Major, I-" Dieter fired into the air.

The report of the pistol crashed around the cathedral vaults, drowning Weber's giveaway words.

"Silence!" Dieter shouted in German.

Weber looked scared and shut up.

Dieter poked the nose of the pistol hard into the face of one of the Gestapo men.

Reverting to French, he screamed, "Off! Off! Get off him!" With terrified faces the two men stood up and backed away.

Dieter looked at Stephanie.

Calling her by Mademoiselle Lemas's name, he shouted, "Jeanne! Go! Get away!" Stephanie began to run.

She circled widely around the Gestapo men and dashed for the west door.

The agent was scrambling to his feet.

"Go with her! Go with her!" Dieter shouted at him, pointing.

The man grabbed his suitcase and ran, vaulting over the backs of the wooden choir stalls and haring down the middle of the nave.

Weber and his three associates looked bemused.

"Lie facedown!" Dieter ordered them.

As they obeyed, he backed away, still threatening them with the gun.

Then he turned and ran after Stephanie and the agent.

As the other two fled through the doorway, Dieter stopped and spoke to Hans, who stood near the back of the church, looking stolid.

"Talk to those damn fools," Dieter said breathlessly.

"Explain what we're doing and make sure they don't follow us." He holstered the pistol and ran outside.

The engine of the Simca was turning over.

Dieter pushed the agent into the cramped backseat and got into the front passenger seat.

Stephanie stamped on the pedal and the little car shot out of the square like a champagne cork.

As they raced along the street, Dieter turned and looked through the back window.

"No one following," he said.

"Slow down.

We don't want to get stopped by a gendarme." The agent said in French, "I'm Helicopter.

What the hell happened in there?" Dieter realized that "Helicopter" must be a code name.

He recalled that Gaston had told him Mademoiselle Lemas's code name.

"This is Bourgeoise," he said, indicating Stephane.

"And I'm Charenton," he improvised, thinking for some reason of the prison where the Marquis de Sade had been incarcerated.

"Bourgeoise has become suspicious, in the last few days, that the cathedral rendezvous might be watched, so she asked me to come with her.

I'm not part of the Bollinger circuit- Bourgeoise is a cut-out." "Yes, I understand that." "Anyway, we now know the Gestapo had set a trap, and it's just fortunate that she had asked me to be there as backup for her." "You were brilliant!" Helicopter said enthusiastically.

"God, I was so scared, I thought I'd blown it on my first day." You have, Dieter thought silently.

It seemed to Dieter that he might have saved the situation.

Helicopter now firmly believed that Dieter was a member of the Resistance.

Helicopter's French sounded perfect, but obviously he was not quite good enough to identify Dieter's slight accent.

Was there anything else that might cause him to be suspicious, perhaps later when he thought things over? Dieter had stood up and said "No!" right at the start of the rumpus, but a plain "No" did not mean much, and anyway he did not think anyone had heard him.

Willi Weber had shouted "Major" in German at Dieter, and Dieter had fired his weapon to drown out any further indiscretion.

Had Helicopter heard that one word, did he know what it meant, and would he remember it later and puzzle over it? No, Dieter decided.

If Helicopter had understood the word, he would have assumed Weber was addressing one of the other Gestapo men: they were all in plain clothes so could be any rank.

Helicopter would now trust Dieter in all things, being convinced Dieter had snatched him from the clutches of the Gestapo.

Others might not be quite so easy to fool.

The existence of a new Resistance member codenamed Charenton and recruited by Mademoiselle Lemas would have to be plausibly explained, both to London and to the leader of the Bollinger circuit, Michel Clairet.

Both might ask questions and run checks.

Dieter would just have to deal with them in due course.

It was not possible to anticipate everything.

He allowed himself a moment of triumph.

He was one step closer to his goal of crippling the Resistance in northern France.

He had pulled it off despite the stupidity of the Gestapo.

And it had been exhilarating.

The challenge now was to make maximum use of Helicopter's trust.

The agent must continue to operate, believing himself unsuspected.

That way he could lead Dieter to more agents, perhaps dozens more.

But it was a subtle trick to pull off They arrived at the rue du Bois and Stephanie drove into Mademoiselle Lemas's garage.

They entered the house by the back door and sat in the kitchen.

Stephanie got a bottle of scotch from the cellar and poured them all a drink.

Dieter was desperately anxious to confirm that Helicopter had a radio.

He said, "You'd better send a message to London right away." "I'm supposed to broadcast at eight p.m.

and receive at eleven." Dieter made a mental note.

"But you need to tell them as soon as possible that the cathedral rendezvous is compromised.

We don't want them to send any more men there.

And there could be someone else on his way tonight." "Oh, my God, yes," the young man said.

"I'll use the emergency frequency." "You can set up your wireless right here in the kitchen." Helicopter lifted the heavy case onto the table and opened it.

Dieter hid a sigh of profound satisfaction.

There it was.

The interior of the case was divided into four: two side compartments and, in the middle, one front and one back.

Dieter could see immediately that the rear middle compartment contained the transmitter, with the Morse key in the lower right-hand corner, and the front middle was the receiver, with a socket for headphone connections.

The right-side compartment was the power supply.

The function of the left-side compartment became clear when the agent lifted the lid to reveal a selection of accessories and spare parts: a power lead, adaptors, aerial wire, connection cables, a headset, spare tubes, fuses, and a screwdriver.

It was a neat, compact set, Dieter thought admiringly; the kind of thing the Germans would have made, not at all what he would expect from the untidy British.

He already knew Helicopter's times for transmission and reception.

Now he had to learn the frequencies used and-most important-the code.

Helicopter plugged a lead into the power socket.

Dieter said, "I thought it was battery-operated." "Battery or mains power.

I believe the Gestapo's favorite trick, when they're trying to locate the source of an illicit radio transmission, is to switch off the town's electricity block by block until the broadcast is cut off" Dieter nodded.

"Well, with this set, if you lose the house current, you just have to reverse this plug, and it switches to battery operation." "Very good." Dieter would pass that on to the Gestapo, in case they did not already know.

Helicopter plugged the power lead into an electrical outlet, then took the aerial wire and asked Stephanie to drape it over a tall cupboard.

Dieter looked in the kitchen drawers and found a pencil and a scratch pad that Mademoiselle Lemas had probably used to make shopping lists.

"You can use this to encode your message," he said helpfully.

"First I'd better figure out what to say." Helicopter scratched his head, then began to write in English:

ARRIVED OK STOP CRYPT RENDEZVOUS UNSAFE STOP NABBED BY GESTAPO BUT GOT AWAY OVER

"I suppose that's it for now," he said.

Dieter said, "We should give them a new rendezvous for future incomers.

Say the cafee La Gare next to the railway station." Helicopter wrote it down.

He took from the case a silk handkerchief printed with a complex table showing letters in pairs.

He also took out a pad of a dozen or so sheets of paper printed with five-letter nonsense words.

Dieter recognized the makings of a one-time-pad encryption system.

It was unbreakable-unless you had the pad.

Over the words of his message, Helicopter wrote the five-letter groups from the pad; then he used the letters he had written to select transpositions from the silk handkerchief Over the first five letters of ARRIVED he had written the first group from his one-time pad, which was BGKRU.

The first letter, B, told him which column to use from the grid on the silk handkerchief At the top of column B were the letters Ae.

That told him to replace the A of ARRIVED with the letter e.

The code could not be broken in the usual way, because the next A would be represented not by e but by some other letter.

In fact, any letter could stand for any other letter, and the only way to decrypt the message was by using the pad with the five-letter groups.

Even if the code breakers could get hold of a coded message and its plain-language original, they could not use them to read another message, because the next message would be encoded with a different sheet from the pad- which was why it was called a "one-time" pad.

Each sheet was used once, then burned.

When he had encrypted his message, Helicopter flicked the on/off switch and turned a knob marked in English "Crystal Selector." Looking carefully, Dieter saw that the dial bore three faint markings in yellow wax crayon.

Helicopter had mistrusted his memory and had marked his broadcast positions.

The crystal he was using would be reserved for emergencies.

Of the other two, one would be for transmission and the other for reception.

Finally he tuned in, and Dieter saw that the frequency dial was also marked with yellow crayon.

Before sending his message, he checked in with the receiving station by sending:

HLCP DXDX QTC1 QRK? K

Dieter frowned, figuring.

The first group had to be the call sign "Helicopter." The next one, "DXDX," was a mystery.

The number one at the end of "QTC1" suggested that this group meant something like: "I have one message to send you." The question mark at the end of "QRK?" made him think this asked if he was being received loud and clear.

"K" meant "Over," he knew.

That left the mysterious "DXDX." He tried a guess.

"Don't forget your security tag," he said.

"I haven't," Helicopter said.

That must be "DXDX," Dieter concluded.

Helicopter turned to "receive" and they all heard the Morse reply:

HLCP QRK QRV K

Once again, the first group was Helicopter's call sign.

The second group, "QRK," had appeared in the original message.

Without the question mark, it presumably meant "I am receiving you loud and clear." He was not sure about "QRV," but he guessed it must mean "Go ahead." As Helicopter tapped out his message in Morse, Dieter watched, feeling elated.

This was the spy catcher's dream: he had an agent in his hands and the agent did not know he had been captured.

When the message was sent, Helicopter shut down the radio quickly.

Because the Gestapo used radio direction-finding equipment to track down spies, it was dangerous to operate a set for more than a few minutes.

In England, the message had to be transcribed, decoded, and passed to Helicopter's controller, who might have to consult with others before replying; all of which could take several hours, so Helicopter would wait until the appointed hour for a response.

Now Dieter had to separate him from the wireless set and, more importantly, from his coding materials.

"I presume you want to contact the Bollinger circuit now," he said.

"Yes.

London needs to know how much of it is left." "We'll put you in touch with Monet, that's the code name of the leader." He looked at his wristwatch and suffered a moment of sheer panic: it was a standard issue German Army officer's watch, and if Helicopter recognized it the game would be up.

Trying to keep the tremor out of his voice, Dieter said, "We've got time, I'll drive you to his house." "Is it far?" Helicopter said eagerly.

"Center of town." Monet, whose real name was Michel Clairet, would not be at home.

He was no longer using the house; Dieter had checked.

The neighbors claimed to have no idea where he was.

Dieter was not surprised.

Monet had guessed that his name and address would be given away by one of his comrades under interrogation, and he had gone into hiding.

Helicopter began to close up the radio.

Dieter said, "Does that battery need recharging from time to time?" "Yes-in fact they tell us to plug it in at every opportunity, so that it's always fully charged." "So why don't you leave it where it is for now? We can come back for it later, by which time it will be charged.

If anyone should come in the meantime, Bourgeoise can hide it away in a few seconds." "Good idea." "Then let's go." Dieter led the way to the garage and backed the Simca Cinq out.

Then he said, "Wait here a minute, I have to tell Bourgeoise something." He went back into the house.

Stephanie was in the kitchen, staring at the suitcase radio on the kitchen table.

Dieter took the one-time pad and the silk handkerchief from the accessories compartment.

"How long will it take you to copy these?" he said.

She made a face.

"All those gibberish letters? At least an hour." "Do it as fast as you can, but don't make any mistakes.

I'll keep him out for an hour and a half" He returned to the car and drove Helicopter into the city center.

Michel Clairet's home was a small, elegant town house near the cathedral.

Dieter waited in the car while Helicopter went to the door.

After a few minutes, the agent came back and said, "No answer." "You can try again in the morning," Dieter said.

"Meanwhile, I know a bar used by the Resistance." He knew no such thing.

"Let's go there and see if I recognize anyone." He parked near the station and picked a bar at random.

The two of them sat drinking watery beer for an hour, then returned to the rue du Bois.

When they entered the kitchen, Stephanie gave Dieter a slight nod.

He took it to mean she had succeeded in copying everything.

"Now," Dieter said to Helicopter, "you'd probably like a bath, having spent a night in the open.

And you certainly should shave.

I'll show you your room, and Bourgeoise will run your bath." "How kind you are." Dieter put him in an attic room, the one farthest from the bathroom.

As soon as he heard the man splashing in the bath, he went into the room and searched his clothes.

Helicopter had a change of underwear and socks, all bearing the labels of French shops.

In his jacket pockets were French cigarettes and matches, a handkerchief with a French label, and a wallet.

In the wallet was a lot of cash-half a million francs, enough to buy a luxury car, if there had been any new cars for sale.

The identity papers seemed impeccable, though they had to be forgeries.

There was also a photograph.

Dieter stared at it in surprise.

It showed Flick Clairet.

There was no mistake.

It was the woman he had seen in the square at Sainte-Cecile.

Finding it was a wonderful piece of luck for Dieter-and a disaster for her.

She was wearing a swimsuit that revealed muscular legs and suntanned arms.

Beneath the costume she had neat breasts, a small waist, and delightfully rounded hips.

There was a glimmer of moisture, either water or perspiration, at her throat, and she was looking into the camera with a faint smile.

Behind her and slightly out of focus, two young men in bathing trunks seemed about to dive into a river.

The picture had obviously been taken at an innocent swimming party.

But her semi nakedness, the wetness at her throat, and the slight smile combined to make a picture that seemed sexually charged.

Had it not been for the boys in the background, she might have been about to take the swimsuit

off and reveal her body to the person behind the camera.

That was how a woman smiled at her man when she wanted him to make love to her, Dieter thought.

He could see why a young fellow would treasure the photo.

Agents were not supposed to carry photos with them into enemy territory-for very good reasons.

Helicopter's passion for Flick Clairet might destroy her, and much of the French Resistance too.

Dieter slipped the photo into his pocket and left the room.

All in all, he thought, he had done a very good day's work.