Abruptly the purple light snapped out.

Footsteps moved. A man's voice. a woman's, then both, whispering together in a guarded conversation he could not hear. Sweat trickled coldly down into his collar. He kept scratching his right palm to jolt himself with fresh waves of stinging pain.

There was a whine, a snap of a switch going down. Solo didn't dare move. He tried to open his eyelids a fraction more, turned his pupils toward the sound of Ahab's heavy breathing. Amplified, a flat male voice said, "Yes, Commander?"

"Stand by with the diving gear. Mr. Solo is under control and ready to go."

Sitting heavy-lidded, Napoleon Solo stared at the carpet.

Briskly, Cleo said, "Mr. Solo, you will obey Commander Ahab's instructions and only Commander Ahab's, whether delivered in person or via a microphone and head set receiver. You will do this starting the moment I count three and clap my hands twice. Furthermore, you will be agreeable. You won't struggle or try to fight or escape." She paused. "Very well, Mr. Solo. One. Two. Three."

Sound of palms cracking together once, twice. Solo affected a silly smile and opened his eyes.

"I'm hungry," he said with a cheerful grin.

Commander Ahab bustled up, touched the chair's back. The steel bands retracted with spanging sounds.

"Sorry, no time for that now, Mr. Solo. We must get you into your gear and on your way."

Tractably Solo allowed himself to be led toward the entrance to the chamber. Illya Kuryakin slumped against the wall, the ugly purple bruise on his forehead showing where he had been clubbed. As Solo passed, Illya gave him a searching look. Solo raised his right hand and wriggled his fingers in the air.

"Hello there."

Illya looked ill as Solo stepped through the hatch.

Moments later Solo was shoved down a ladder into a large, steel-walled room where half a dozen THRUSH seamen manhandled him into a cumbersome diving suit. A diving helmet was lowered and dogged down. The inside of the suit smelled vaguely of fish. Solo's field of vision was restricted. THRUSH sailors crisscrossed it, carrying air hoses.

His head was jarred as the seamen jerked the helmet one way, then another, attaching the hoses. Ahab appeared. He had a combination earphone-mike on his head, the mike a tiny black sphere at the end of a curving piece of stainless steel which swept around from his ear to just in front of his lips. Ahab held up a small, flat, shallow package with a metal clip attached.

"Explosive. Very powerful, Mr. Solo." Ahab's words crackled through the diving Suit headset. "I will fasten it securely to your belt, thus."

The package was clipped in place.

"Attached to the package is a special trigger-release weight. You will have no trouble feeling the stud which activates the weight. I will tell you when to press the stud. You will be going down quite a long distance, and when you reach the proper level, we will give you further instructions.

"Follow them to the letter, Mr. Solo. The placement of this particular charge is extremely critical. An error of even a few feet could upset calculations. We trust the pressure to which you descend will not prove fatal, but if it does—ah, well, you have given your life to a good cause."

That's one cause, Solo thought as he grunted a monosyllabic reply, that won't get any help this trip.

He'd fooled them.

His right hand, inside the suit's glove, still stung. But he had managed to hold out against Cleo St. Cloud. He hoped Illya could take care of himself, escape somehow. Illya would be going it alone now. Solo knew, as he was shoved forward to an open hatch, that his trip would probably be one way.

He was going to place the explosive packet in the wrong location if it killed him. As it very likely would.

The THRUSH seamen pushed him into an oval chamber, then sealed its inner hatch. Water began to rise, foaming dark around his boots. Solo turned clumsily, noting that his air hoses were paying out through the otherwise sealed hatch running out through specially gasketed steel ring brackets.

The water rose past his faceplate. Evidently activated by the agitation of the sea water pouring in, a powerful lamp flashed on at the top of his helmet. The outer hatchway opened.

"Forward, Mr. Solo!" Ahab said in the headset. "Over the threshold and down to Davey Jones." Ahab's voice carried a malicious edge.

Manfully Solo moved ahead. Once away from the steel hull of the Moby Dick he dropped at a slow but steady rate. Out of the deepening watery gloom something long, bullet-shaped, and finned flashed at him. Solo slung himself to one side.

The monster fish flashed on by, snapping its mouth shut on a disturbing display of sharp teeth. The gloom of the deeps closed around him again, shading off from purplish green to total black.

The beam of his head lamp revealed little. He had distressing visions of fanged fish hovering nearby, waiting to make a snack of him. He began whistling Minnie the Mermaid, hoping Ahab was listening.

Sure enough, he was: "The pitiful dupe! He's whistling a bawdy sea song. Cleo my dear, you gave an inspired performance."

All this was aside, not meant for Solo, who was surrounded by watery darkness and beginning to find it difficult to maintain a mood of levity. He was troubled by fear of what would happen if he failed; fear of the tremendous psychological advantage the tidal wave technique would give to THRUSH; fear, at the last, of his own death, down here in the primordial ghostliness of the sea, alone, powerless, small.

Then he began to understand Ahab's earlier remarks about the riskiness of this mission. Inside his suit, seeming to issue from behind him, he heard slight tearing sound. Slight, but loud in his ears as a butcher knife slashing canvas.

Immediately the air he was breathing seemed thinner, malodorous. He began to breathe more loudly than before. His lungs hurt.

"Solo!" Ahab said. "The pressure indicator is behaving oddly."

"Air—beginning to smell bad coming into the suit," he said in a flat voice.

Over the headset Solo heard someone in the sub say that he was nearly to demolition depth. He also caught a snatch of a sentence ending with the words pop like a balloon.

His ears had developed a ringing. Pale blue spots danced behind his eyes. Was the crushing pressure slowly ripping through the multi layered suit? He was still descending, but through total blackness, except where the headlamp speared.

The soles of his diving boots crunched against something solid. Solo bent his head downward. The spotlight illuminated a dark, wetly green rock shelf on which he had come to rest. Ahab spoke again:

"Mr. Solo, can you hear me?"

Solo grunted that he could.

"Very well. Listen carefully. You will turn to your right. Repeat, to your right. Tell me what you have executed a ninety-degree right turn."

Swallowing to drive the blue dancing spots away, Solo turned ninety degrees.

To the left.

"I've turned," he croaked. His throat felt clogged with foul air.

"Now you will walk fourteen paces straight ahead. Each pace will be measured thus. Put your right foot down. That is a pace. Move your left foot so that the heel rests against the toe of your right. That is your second pace. So on. Report as soon as you completed the maneuver."

Carefully Solo followed the instructions. He was growing dizzy and weak. Seven paces.

Eight.

Nine.

Ten—then thirteen—and fourteen.

"I've taken fourteen paces." His voice sounded rougher than ever.

"All right. Now remove the explosive packet from your waist. Report when you have done so."