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 belly-up 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.