He did. Fish so far from their normal environment would not have migrated unless they'd been forced to. So these fish must have been driven up from the blissful utter blackness of the abyss, which was their habitat. He had a vivid memory of the kind of urging they'd received, because of his recent swim outside the reef opening. That was the experience he believed they shared. He got his catch onto the _Esperance's_ deck and found some sharp knives in the galley, while Doug put the aqualungs away. When Doug came abovedecks again, he looked distastefully at the work Terry had undertaken. "Do you like to do that sort of thing?" he asked. "Hardly!" said Terry. "But I want to get it done." Doug watched for a moment or two. "I'm pretty keen about poetry. Sometimes I feel I've got to sweat over a poem that I need to get written. It's hard work. There's no real sense to it. But I feel it's got to be done. I guess that's the way you feel now." "Perhaps," said Terry. It wouldn't have occurred to him to liken the writing of verses to the dissection of dead deep-sea fish, but Doug had a point. He went away presently, and Terry completed the highly unpleasant task. He had just finished flushing the deck clean when Deirdre came back from the tracking station. He was already at work on the recorder when she stepped onto the deck. "You didn't stay," said Deirdre. "I was waiting for a chance to tell my father about the hum outside the lagoon, but he was as deep in the meteor argument as any of them. I still haven't told him." "There's something else to tell him now," Terry remarked. "I went down with an aqualung. Doug was standing by," he added at her gesture of protest, "and speared some fish that don't belong here. I've dissected them. Their swim bladders had been very skillfully punctured, so if they went or were driven into lesser pressure, they'd leak instead of bursting. That's how they survived coming up from the depths. But the main thing is this." He held out a small plastic object in his hand. It was about an inch in diameter and two in length, and there were inclusions in the clear material. There were plates and threads of metal. They had that look of mysterious purpose that highly-developed technical devices have. "This was fastened to the fin of a fish that belongs as far down as a fish can go," he said. "I've found out one of its purposes. When it is in the water, it makes a sound more acute than a whistle every time another sound strikes it. Try that on your piano!" Deirdre stared. "I'm saying," he repeated, "that it takes in one sound and gives out another. It's ... it could be a relay. What is that for? What's it all about? What does it mean? And I ask just those questions because I don't dare ask who and why!" "What ... what will you do?" asked Deirdre absurdly.