Somewhere up ahead their youthful guide felt for a gate that might or might not be charged with lethal current. She took another breath. He'd been right about the tides. In some places there wasn't enough room to get one's head above water. In such spots she had to turn on her back. Then she would drift with only the upper part of her face above water, sometimes scraping the cold stone of the roof as she drew in long draughts of moist, stale air. Then it was turn, dive, and swim, heading for the next air pocket, pushing off the wall for a little extra distance and hoping she wouldn't miss it.

That happened only once. She surfaced and the air pocket was a blob of water-weed. She had to swim frantically ahead until a small pocket appeared. Panic would have used too much air, so she stayed ever so calm.

It was indeed totally black-cave-black, coal-sack black-in that tunnel. Blacker than the inside of your eyelids when closed. The only light in that mile-long, days long swim was the glow from her own wrist chronometer. A numerical firefly, it followed obediently, seeming a separate existence and not a part of her arm.

A few eons later, her outstretched right hand encountered something hard and cold. There was enough clearance so that her shoulders could rise out of the water. She held onto the grating for several seconds.

Then she remembered that if certain circuits were reconnected, thousands of volts could shoot through the damp steel. She let go hurriedly. A voice sounded on her right.

"Hinges are a little stiff, Miss Kai-sung." It was Philip. "Ah, there!"

A moment later something broke the surface on her left with a loud whoosh. It was Hammurabi. He was followed seconds later by a thin whistle: Porsupah. Even the Tolian was panting. Not because of fatigue, but because the air here was anything but fresh.

"Everyone okay? All right, I'm going down to lift the gate," said the youngster. "Miss Kai-sung, you and Porsupah-al wait ten seconds and come after me. This tunnel descends slightly and then opens into the sea. It's not a long drop, just deep enough to ensure that the outlet opening is always hidden from surface view. The shore here is pretty rocky. Find a spot shielded from land. Captain, after they've slipped out I'll resurface inside. Then you follow me down. I'll be holding the grating open from the sea side. When you feel the bottom of the grate, tap it with your watch and trail the body just behind you. I'll hear it and let the gate drop. It ought to hold the corpse to the seafloor solidly."

Without waiting for comment the youth hyperventilated, then ducked under. Porsupah and Kitten counted off the seconds together and followed. Water splashed the perpetually moist walls and Mal's face. Several millennia later Mal heard the youngster break surface.

"Ready, Captain?"

Mal took an unbreakable grip on the corpse's neck with his right hand. "One question. I'm no herpetologist, but I don't recall noticing any gills on your scaly companion."

"Oh, Pip? I discovered-quite by accident-that he can go without oxygen for a surprising amount of time.

Some day I'll run across a xenoherpetologist who can explain it to me. I'm going now." Deep breathing, an echoing splash in the confining air bubble. Mal followed shortly, the tech's body a tugging, naggingly buoyant parasite. Fortunately, as Philip had said, the gate didn't go deep. He felt for and encountered the prongs at the bottom of the grating. Carefully, he eased the body bellyup against them, then tapped one-two-three times with his wristband. The grating immediately dropped with surprising speed, pinning the unlucky, unnamed man to the muddy channel bottom.

Immediately Mal turned and swam, away and downward. He could feel pressure waves from another body swimming alongside. The shipmaster had a moment of worry. When the power to the gate was switched back on, the body jamming it open ought to trigger every alarm on the island.

But by that time they'd be long gone.

They'd better be. The two men broke the surface together. Only one moon was still in the sky, but there was enough light to make out two dim figures on shore, huddled close by an overhanging block of gneiss.

Two shadowed faces, one human and the other not, stared back. Mal and Philip swam over and hugged the boulder, catching their breath.

"Nice to breathe fresh air again," said Mal,

"Yeah. I'd like to rest too, but in the city. I'll feel a lot better when were on board that hoveraft of yours."

"Which direction is the inlet?" Kitten whispered. "My Sense of direction is scrambled:"

"Just around that point," the youngster replied, pointing ahead. "The island's not very big, but parts of the complex go quite deep. Miss Kai-sung, you and Porsupah] don't know where the Captain's raft is beached, so be sure and stay close. The harbor is crowded enough to be confusing."

"Don't lecture me, my skinny samaritan. I'm a big girl now."

"What about harbor patrols and interior alarms?" Mal asked, to change the subject.

"Aren't many this close in. There is a transceiving shield, quite illegal-and efficient. Our best bet, therefore, is to get out of the landing proper and skim like hell until we pass the defense perimeter. Then we can cast unblocked to the Rectory in the city. Once they pick us up, his Lordship should be too busy packing to worry about us."

"You hope," said Kitten.

"The best of all possibilities," he replied. He began paddling towards the point of land he'd indicated.

"Any other vessels expected tonight?" Mal asked, swimming close behind.

"I don't know for sure, but I don't believe so. Why?"

"Going by your description of Rose's setup and what I know of similar ones, this defensive situation is designed primarily for detecting boats trying to get in. It just might ignore any going out. With luck it will be quite a while before anyone notices our disappearance."

As they moved up the inlet, hugging the shoreline, Kitten couldn't escape the feeling that Rose was watching from somewhere in the trees. At any moment a light would lance out from the shadows and spear them with its unblinking glare. But they reached the raft landing without anything other than a few disturbed mollusks detecting their passage.

There were few lights on at the artificial beach. Nothing moved. Philip led the way up the pebbled plastic sand cover. No one stopped him to ask what a sanitation engineer was doing out for a late-night swim-in full workwear. A gesture brought the others out of the water. Slick and hard, the plastic gave excellent purchase to hover vehicles. The little group had no trouble making their way towards the beached rafts, although there were places where some frantic scrambling was necessary. They huddled next to the deflated sac of one raft.

"I can make out one guard at the head of the loading pier," Philip whispered. "We ought to be able to slip inside your craft without his noticing us."

"I'd rather make sure he doesn't," said Mal. He disappeared quietly under the metal piering. Several minutes passed while the others waited and the moonlight grew dimmer. The dot that represented the guard abruptly doubled in size, then disappeared completely. After a short pause, Mal's voice floated across from the rampway of his raft.

"All clear now. Philip, you boost Miss Kai-sung and Porsupah up, then I'll pull you in."

It was a short dash to the side of the raft. Kitten felt two massive hands envelop her wrists. Suddenly she was standing on the ramp alongside the Captain. A second later Porsupah, then Philip, appeared.

"What about the guard?" Philip asked.

Mal was opening the lock. "Under the pier, in a clump of bushes. He shouldn't be spotted. Still, he might be required to report in on who knows what schedule? We'd better move." He noticed the young man's gaze still on him. "No, I didn't kill him."

The door swung back to reveal bright light and the muzzle of a small gun. It was wielded, fortunately, by a familiar small man.

"You gave me a start, Captain," said First Mate Takaharu. "I wish you'd apprise me in advance of these middle-of-the-night parties."

Mal moved past him to the center control console. He flipped switches, began warming the drive fans as gradually and quietly as possible. "Wasn't practical this time, either, Maijib. Neighbors would have resented not being invited. Lieutenants Kitten Kai-sung and Porsupah, Philip-my First Mate, Maijib Takaharu. You should all exchange greetings later, but just now let's get the shining hell out of here ...."

He gunned the engines all at once, throwing everyone for the nearest support.

The raft backed at high speed into the water, sending a shower of spray across the inlet. Gears whining in protest, the little craft spun 360. Skimming the surface at 200 kph, it kicked up a wall of faintly phosphorescent spray as it shot out of the harbor. A few night-prowling mudducks saw it go.

"I don't recall sending for you, technician."

The man in the blue serge uniform was obviously badly frightened. Also out of breath. "Your pardon, Lord. The two suspected Church agents and the freighter Captain you ordered held with them have disappeared."

Two birds sang in a cage to one side of the room. Rose turned and stared at them. One was bright blue, slightly milky like chalcedony. The other was a mottled yellow. He watched them for a while before pivoting back to face the tech.

"They've left the island." It was not a question.

"It must be so, Lord. The hoveraft the freighter Captain arrived in is missing from its landing. The guard assigned to watch was found under the piering nearby. He was paralyzed, but the meditech believes he will recover."

"How awkward all around," Rose replied evenly. He had given no evidence of upset, evinced no loss of control. He was too old for that now. "Is it known how this was done?"

"Two men stationed near the confining suite were found dead in a service alcove. A check of the central recorder indicates that a portion of the immediate island restricted perimeter, specifically the gates protecting the water intake and sewage outlet channels, were powered down for some thirty minutes earlier this morning. A subsequent check of personnel revealed that two men, an apprentice sanitation engineer and a senior biotech, were missing. The body of the latter was discovered jamming open the gate guarding the sewage outflow channel. Also, one of the first two fatalities displayed clear evidence of both acid attack and nerve poison. The engineer was known to keep a poisonous reptile with him at all times."

"Quite ingenious,". Rose murmured. He turned and depressed one of many switches set inconspicuously in the arm of a luxuriously upholstered couch. The ceiling of the exquisitely wrought bird cage began to move gently downwards.

Rose spoke without turning. "Any indication of how long ago the craft left the harbor?"

"Computing from the time of the power lapse and that of the pier guard's last report, Lord, it is estimated they have been gone now for about an hour."