“What do I do with the body? Like you say, the current carries sewage away. But this island isn’t big. I wouldn’t want some detection device to discover it floating about Rose’s defense perimeter while we’re trying to reach the raft.”

“When we leave the gate, I’ll hold it up while you center it underneath,” said Philip. “The grating will pin it on the bottom securely enough.” He put a hand on either side of the opening, slipped into the gentle flow. “I’m going to replace the panel from underneath. Since the bolts are clear plasticine, too, it won’t show tampering unless someone looks hard right at the seals.”

“You’re awfully proficient at escapes for . . .”

“ . . . an apprentice sanitation engineer?” The youngster grinned. He helped Mal lower the limp body into the water. “I read a lot of cheap adventure stories.” He reached up. Despite his height, he had to jump to grab hold of the edge of the removed section of doming. Successive jerks and tugs, with Mal holding him around the hips, slid it neatly back in place over their heads.

“What about this ‘gate’ you keep talking about?” asked Kitten. “With the power turned off, will it open?”

“Oh, it can be raised manually, all right. The positive charge it normally carries is considered sufficient to discourage nosy visitors, intelligent or otherwise. Nothing so crude as a manual lock on it.” He turned and let himself drift into the brackish flow, moving easily with an occasional long, sinuous stroke. The others followed.

The water in the channel was comfortably warm, a carry-over from the sewage sterilization procedure. Still, Kitten found herself shivering slightly. There were no lights in the long cave and darkness was total. She swam with slow strokes, letting the current do most of the work. Now and then her hand would give notice of a slight bend in the channel. The youth hadn’t mentioned anything about side tunnels, so she wasn’t afraid of fumbling off into some fish-trap or heat chamber—much. She could sense pressure waves from a large mass moving parallel on her right. The faintly neanderthalic ship-captain, no doubt. She recalled how easily, accidentally, the big man had snapped the technician’s neck, and mentally resolved to put a moratorium on all threats of arm-breaking.

Porsupah was somewhere behind. Being capable of swimming circles around any of them, it was decided that he should follow at a distance. This would enable him to give them a little time if any pursuit should develop. That beggared the fact that there wasn’t a thing they could do about such pursuit, but it seemed too reasonable an idea to ignore.

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.