They had built organic hinges, deep-sea muscles into their infrastructure. He was stuck in the thicket and the harder he pushed, the worse the tangle got.
He stopped pushing. He wasn't going to get anywhere this way.
He still had his narrowband connection to the row-boat. Why hadn't he thought of that beforehand? Stupid meat-brains — no room at all for anything like real thought. Why had he venerated them so?
"Robbie?" he transmitted up to the instance of himself on the surface.
"There you are! I was so worried about you!" He sounded prissy to himself, overcome with overbearing concern. This must be how all Asimovists seemed to humans.
"How far am I from Kate?"
"She's right there! Can't you see her?"
"No," he said. "Where?"
"Less than 20 centimeters above you."
Well of course he hadn't see her. His forward-mounted eyes only looked forward. Craning his neck back, he could just get far enough back to see the tip of Kate's fin. He gave it a hard tug and she looked down in alarm.
She was trapped in a coral cage much like his own, a thicket of calcified arms. She twisted around so that her face was alongside of his. Frantically, she made the out-of-air sign, cutting the edge of her hand across her throat. The human-shell's instincts took over and unclipped his emergency regulator and handed it up to her. She put it in her mouth, pressed the button to blow out the water in it, and sucked greedily.
He shoved his gauge in front of her mask, showing her that he, too was in the red and she eased off.
The coral's noises were everywhere now. They made his head hurt. Physical pain was so stupid. He needed to be less distracted now that these loud, threatening noises were everywhere. But the pain made it hard for him to think. And the coral was closing in, too, catching him on his wetsuit.
The arms were orange and red and green, and veined with fans of nanoassembled logic, spilling out into the water. They were noticeably warm to the touch, even through his diving gloves. They snagged the suit with a thousand polyps. Robbie watched the air gauge drop further into the red and cursed inside.
He examined the branches that were holding him back. The hinges that the reef had contrived for itself were ingenious, flexible arrangements of small, soft fans overlapping to make a kind of ball-and-socket.
He wrapped his gloved hand around one and tugged. It wouldn't move. He shoved it. Still no movement. Then he twisted it, and to his surprise, it came off in his hand, came away completely with hardly any resistance. Stupid coral. It had armored its joints, but not against torque.
He showed Kate, grabbing another arm and twisting it free, letting it drop away to the ocean floor. She nodded and followed suit. They twisted and dropped, twisted and dropped, the reef bellowing at them. Somewhere in its thicket, there was a membrane or some other surface that it could vibrate, modulate into a voice. In the dense water, the sound was a physical thing, it made his mask vibrate and water seeped in under his nose. He twisted faster.
The reef sprang apart suddenly, giving up like a fist unclenching. Each breath was a labor now, a hard suck to take the last of the air out of the tank. He was only ten meters down, and should be able to ascend without a stop, though you never knew. He grabbed Kate's hand and found that it was limp and yielding.
He looked into her mask, shining his light at her face. Her eyes were half shut and unfocused. The regulator was still in her mouth, though her jaw muscles were slack. He held the regulator in place and kicked for the surface, squeezing her chest to make sure that she was blowing out bubbles as they rose, lest the air in her lungs expand and blow out her chest-cavity.
Robbie was used to time dilation: when he had been on a silicon substrate, he could change his clockspeed to make the minutes fly past quickly or slow down like molasses. He'd never understood that humans could also change their perception