"It's 450 now."

"A bad stretch," said Bonnett. "You'd expect the EPs to be ranging this area in net formations."

Garcia slipped into the control room. "Les."

"How is he?"

"Are you sure it was just one minute over?"

"Certainly I'm sure. What's wrong?"

"Very low white count. It looks like closer to half an hour over."

"Any burns?"

"No indications yet."

"It could be that he didn't recover well from handling that Security lieutenant," said Ramsey.

"That's what I was thinking," said Garcia. "I gave him a sedative and a booster shot of de-sulph and de-carb."

"Good." Bonnett turned to Garcia. "Stick by him until I call you."

"Righto." Garcia ducked back through the door. Bonnett's in command, thought Ramsey. We never thought of that. Can he adjust to the job? And then another thought: Good Lord! What if he's the sleeper? He studied the first officer covertly out of the corners of his eyes.

The Ram sped onward. "Depth 550 fathoms," said Ramsey. Bonnett shifted the Ram's diving planes, took them down to 500 fathoms in a low glide. He brought the deck level when the pressure gauge read 1300 pounds to the square inch.

"Twenty minutes," said Ramsey.

"Give or take a few," said Bonnett. "What's wrong with Joe? Why doesn't he let us know how the skipper is?"

"You didn't tell him to," said Ramsey.

"Yes, but --"

"There's most likely nothing to report. It's too soon."

"Get him on the intercom."

Ramsey shrugged, thumbed the switch on his chest mike: "Joe?"

"Here."

"How's the skipper?"

"Still sleeping. I'd give a pretty to know what the overdose actually was."

"Did you check his suit dosometer?"

"Right after he got out of the tunnel. Slight overage, just as Les said. You know, I'm no medical chap, but I'd bloody well swear that he'd gotten contaminated atmos."

"How?"

"I don't know, really. I saw him check suit pressure before going in. It was still holding when he came out. I'm certain there were no leaks."

"Did you snoop the tunnel filter system?"

"That's what I'm worried about, Johnny. I naturally assumed --"

Bonnett interrupted, speaking into his own microphone: "Can you leave the skipper?"

"Yes. He's resting quietly."

"Get forward and snoop that filter."

"I'm on my way."

Bonnett turned to Ramsey. "There's a lesson for you and I'm ashamed to say it of Joe: Never assume anything. You have to know!"

"Couldn't he assume that the tunnel's filter system was okay?"

"Well . . ."

"We assume a lot of things about our little world."

"The perfect ecology," muttered Bonnett. "Self-sustaining."

Garcia slipped into the control room, went out the forward door without speaking.

"If that filter system is leaking," said Bonnett, I'll --"

"Signal!" Ramsey slapped the cut-off switch, silencing the drive. The Ram drifted. "Quartering to the east." He narrowed down the tuning band. "Pack. There's more behind us!" He rotated the finder band. "More at 340."

"Boxed!" said Bonnett. "Have they spotted us?"

"Can't be certain. No collision courses."

"What's the depth?"

"Reading now 680 fathoms. We're on the edge of the basin."

Bonnett engaged the drive, eased them forward at minimum speed. "Tell me the instant you detect a change of course from one of those signals."

"Aye."

Garcia's voice came over the intercom. "Les?"

"What is it?"

"Filter's cool, but the inner hose line shows a slight leakage."

"How much?"

"Sixty m-r. I make it a thirty-eight minute overdose."

"Where's the leak?"

"Inside somewhere. Maybe that broken control arm slapped something. I can't tell from here."

"Dog the hatch and come up here. We're ranging an EP signal."

"Righto. I heard you slip the drive."

Bonnett turned to Ramsey. "Depth?"

"Something over 7200 feet. Shelving off rapidly. Les! That pack behind us has changed course." Ramsey worked over his dials. "They've closed the angle, but they're not headed for us."

"It could be a trick! We can't chance it." He fed more power to the drive. The Ram picked up speed.

"They're on us! They've altered course, increased speed."

Bonnett pushed the drive control to its limit. They felt the straining of the giant engines.

Garcia stepped into the control room, wiped a spot of grease from his hand, looked at the searchscope. "Have we had it, chaps?"

Bonnett ignored him. "Depth?"

"A little over 1500 fathoms. I'd make it about 9100 feet." Ramsey reset a dial beside the searchscope. "The pack to our east has changed course. They are now on collision heading."

"It was nice knowing you, gentlemen," said Garcia. "We can't turn east or south," said Bonnett. "Bottom is 2000 feet below our limit."

"I'm getting an interference reading at 8400 feet," said Ramsey. "Seamount. Heading 215 degrees."

"It might just as well be 84,000 feet," said Garcia. "That'd be something like 3600 pounds to the square inch, almost 600 over our limit."

"They'll be in firing range within a half hour," said Ramsey. He glanced at Bonnett. "What happens to the pressure hull coefficient if we boost internal pressure beyond ten atmos?"

"We wouldn't be alive to enjoy it," said Garcia.

"Maybe," said Ramsey, He slipped his vampire gauge from its belt case, locked it onto his wrist, shot the needle into his vein. "How long would it take to draw everything but the oxy out of our atmos?"

"Pure oxy?" Garcia appeared startled.

"What's on your mind?" asked Bonnett.

Ramsey said, "Put the anhydrase generation on manual and balance it by sight." He nodded toward the gauge on his wrist.

"What do the medics say about that?" asked Garcia.

"Nothing certain," said Ramsey. "I've heard it argued both ways." He glanced at the scope in front of him. "I think it may be our only chance."

"Joe, take over here," said Bonnett. He stepped away from the controls as Garcia took hold of the helm.

"What're you going to do, Les?"

"Unhook the governor from the anhydrase generator system."

Garcia's head jerked around. "You're not paying serious attention to this punk's suggestion!"

Bonnett already was removing the cover plate from the atmosphere controls. "I am."

"That's suicide."

Bonnett looked to the scope in front of Ramsey. "We're already dead. What do we have to lose?"

He put the cover plate carefully on the deck, returned to the maze of wiring which had been revealed.

"It's those red primaries at the top," said Garcia.

"I know," said Bonnett. He reached in with cutter pliers, snipped the wires. "Do you think the skipper's all right?"

"This is no time to worry about that."

Bonnett nodded, adjusted a pump control. "Johnny, what's the helium reading?"

"Point four."

Bonnett took out his own vampire gauge, adjusted it on his wrist. "Joe, take us down. Heading 215 degrees. Johnny, how far to that seamount?"

"Six minutes."

Bonnett's head snapped up. "You been working time-over-distance in your head?"

Ramsey busied himself with the search controls as the Ram's deck slanted downward. "Yes."

"We'll make a submariner out of him yet," said Garcia. He looked at Bonnett. "Are you sure it wouldn't be better to try floating up again?"

"They're too close," said Bonnett. "Besides, I'm afraid to take another chance on rolling. We sheared off the damper-control base in there." He nodded toward the bow. "No telling what we did to the pile base."

Garcia wet his lips with his tongue.

"Won't they hear us go down?" asked Ramsey.

"They know our depth limit," said Bonnett.

"This was your idea," said Garcia. "Are you getting cold feet?"

Ramsey swallowed.

"Their metal detection is poor," said Bonnett. "I'm counting on their thinking we've taken the deep six rather than risk their fish."

"They won't hear any breaking up noises," said Garcia.

"We hope," said Ramsey.

Garcia paled.

Ramsey looked to the big static pressure gauge. "Outside pressure 2900 pounds." He glanced at Bonnett. "Skipper."

"We have only one skipper," said Bonnett. "He's aft in sick bay."

"No, I'm not!"

They whirled. Sparrow stood in the aft doorway, hand on the metal rim, face pale and beaded with perspiration. "What is the situation, Les?"