"We can only try," Illya said. He stretched out his hand and grasped one of the levers on the control panel. "Let's see what E.l will do…"

"I wouldn't, Mr. Kuryakin. I really wouldn't." The voice came from behind them.

Together, they whirled. Zigzag lines chased themselves across the screen of a small monitor television set just above the shattered window. Above it was a fixed, closed-circuit camera. The voice had undoubtedly come from here.

"It may not do what the label says, you see," the voice went on. "Because although you have unfortunately incapacitated the man we left behind us, he had done his work first."

"I have no idea what you mean," Illya said, looking directly at the camera. Below it, white patches streamed across the screen, to coalesce and finally assemble with the darker zigzags into a picture of three men and a woman sitting behind a control panel similar to the one behind him. The woman was the one who had been in the chamber; the men were Moraes, Hernando, and the man with the skull-like face. It was the latter who was speaking.

"I will tell you," he drawled. "Ah - I see from your face that you can now see us. We have been able to see you all the time… When you burst in and interrupted our meeting, you may or may not have heard the lady here report that she had delivered two prisoners some where, a man and a woman."

"Well?"

"The place she had taken them to was the submarine pen."

"I'm afraid I don't see -"

"Where she had left them and double-locked the exit doors. There is now no conceivable way in which they can reenter the fortress."

"So?"

"The man is your colleague, Mr. Napoleon Solo; the woman is a foolish girl who for some reason tried to help him."

Illya caught his breath. "Even so," he said, "I don't quite -"

"We now come back to Schwarz, the man we left behind," the leader with the skeletal face said smoothly. "You may have heard me instruct him, at one point in the proceedings, to put Plan D into operation?"

"Okay, I'll bite," Kuryakin said, the hairs prickling on the nape of his neck. "What is Plan D?"

"An emergency plan evolved in case anyone should temporarily take over the control room. It is very simple: Schwarz merely disconnected some of the leads from the controls - and then replaced them in a different order."

"And that means?" Illya asked with a dry mouth.

"That when you pull lever A or twist Knob E, you may not now observe reaction A or reaction B on the indicator screens. Not necessarily. You may operate lever A and set in train reaction X."

The agent stared at the screen, his mind racing.

"You might find - to give a more concrete example - that you twisted a knob to open the gates to a tunnel... and succeeded only in flooding a submarine pen. Which would be awkward for your friend Solo."

There was a long silence.

Kuryakin turned and walked to the trapdoor, looking down into the room below. All along the back wall, metal housings like giant fuse boxes hung open - and inside, festooned like the fronds of anemone and weed in some fantastic undersea pool, he could see hundreds upon hundreds of strands of wire in dozens of different colors.

"And not one of those leads is labeled," the voice went on. "Nor are the leads above and below the connection boxes necessarily the same color or combination of colors."

It was quite true. From where he stood, Illya could see. He deliberately turned his back on the TV monitor and surveyed the control board. Any of the wheels or levers whose function, according to the coded numerals and letters on them and repeated on the indicator above, was to open or shut doors, operate fire extinguishers, raise or lower screens or put magic eye circuits out of' operation... any of these might in actuality open sluices which could bring thousands of tons of water in upon the defenseless Solo and his companion in their subterranean prison.

"You've been lucky so far," the voice said persuasively. "You have managed to seal off a good proportion of our forces because the watertight bulkhead doors are excluded from Plan D - for obvious reasons of security. But will you be so lucky next time?"

"Look. I don't know who you are." Illya began, still with his back to the camera.

"The name is Wassermann. A member of the Council of Thrush, along with Senhor Moraes and Hernando here. We are but three of many. You cannot possibly succeed against us. Why do you not simply give up? The odds are too heavily stacked against you."

For answer, Kuryakin reached out and grasped a lever.

"Illya!" the girl cried. "You can't! Surely -"

"Be quiet!" the agent rasped. "Remember what Waverly said."

"Never mind Waverly. You can't take the risk."

"I said be quiet."

"You are foolish, my boy." It was Hernando speaking now. His lined face was in close up on the monitor screen. "We are in a small extra control room here, next to the radio room. We cannot overrule any actions you take - but they are duplicated on our indicators. Think. You may bring death to your friends with that little lever; you may cut off the oxygen supply to the whole fortress; you may douse the room you are in with foam; you may over-fuel the reactor…"

Kuryakin set his teeth and pulled firmly on the lever.

"Watch the big board in the corner," Wassermann said. "The pen is an oblong at the moment glowing in green. The reactor is a red circle below it. If it is over-fueled, the red glow becomes intermittent. When water is admitted to the pen, it goes blank, then slowly fills with blue."

The agent's eyes were sternly fixed on the small indicator in the lid of the cabinet before him. He was staring at the red bar marking what he thought was the close exit to the tunnel - waiting for it to go green.

A sharp cry from the girl dragged his eyes to the other board.

The rectangle symbolizing the submarine pen was no longer green. As he watched, horrorstruck, a luminous blue line appeared at the bottom of the oblong, slowly thickening upwards.

With a smothered exclamation, he seized the lever and struggled to push it back up again. There was a chuckle from the television screen. "Oh, no, Mr. Kuryakin" – it was Moraes speaking this time – "you cannot do that! The action is irreversible. Think it out. There must be a censor overriding all controls while the place is filling: we could not have water levels rising and falling like yo-yos with expensive machinery like nuclear submarines in there, now could we? The 'Exhaust Pen' control will remain inoperative until thirty minutes after the chamber is full. To make sure nobody can empty it while the craft is maneuvering, you know. By which time, of course, your friend..." He shrugged eloquently.

There was a click and the sound went off. The vision dwindled to a tiny white square, brightened for an instant, and then vanished.

Illya dashed to the trapdoor, jumped to the floor below, and began frenziedly searching among the gaily colored leads. But Wassermann had been right: the task was hopeless. There were hundreds. It would have taken an expert electrician hours to trace them all back and check the altered connections through the fused junction boxes. Dispiritedly, he turned and hauled himself back up the ladder. The girl had set her back to him - and the oblong on the indicator board was blue more than three-quarters of the way up.