He looked for Brian and saw him some way off, having abandoned the halibut for what looked like an angel shark. It was a good find, but Ben could see that Brian was already nearly twenty feet deeper than he should be and showed no sign of coming back. Ben then looked for Caddie, fully intending to meddle this time if she seemed to be following Brian and the shark.

She was not near the tube worms nor was she anywhere that he could see. Alarmed, he looked up and saw her. She was perhaps fifteen feet from the bottom. Her hands were jerking frantically as she tried to use a swimming stroke, but she made little headway. Something was wrong. She was clearly trying to get to the surface but had apparently forgotten that the weights in her BC pockets made that impossible. She could accomplish it if she inflated her BC, but she seemed to have forgotten that. Or she’s run out of air, Ben realized.

He swam toward her as quickly as he could. As he did, Caddie seemed to remember the weights in her BC. Her fingers reached for the clips, even as Ben screamed through his regulator, uselessly, for her to stop. It would make her too buoyant.

He saw one pouch drop to the sand, and Caddie began to rise. He kicked harder, stretching out his hand. Caddie, twisting to reach the other pocket, turned so that she was looking at him. Her eyes were wide, and he saw that she was gasping for breath, trying to pull any remaining air out of her tank. He waved at her, but her eyes saw nothing. She dropped the second pouch just as he reached her. Although her body rocketed up, he managed to grab hold of her legs, wrapping his arms around them. Still she flew. He heard the warning beep of his computer begin screaming for him to slow down. He ignored it, crawling up Caddie’s body. He could give her air if he could just reach her. But the water was rushing by so quickly that he couldn’t see.

Let her go. The words of his instructor certifier rang in his ears. It was one of the cardinal rules: If a student began an uncontrolled ascent, it did no good to put yourself in danger by trying to hold on. The rapid decrease in depth put you at enormous risk for decompression sickness or an embolism, and it helped no one if both divers took a hit.

Caddie, however, was not just another diver. He couldn’t watch her shoot away from him like a falling star while he stayed safely underwater. In the time it would take him to ascend safely, she could die.