Terry turned to the chart rack. He pulled out a chart and looked up the position. Someone had made a pencil-dot there. It was close to Thrawn Island, on the very brink of the Luzon Deep, that incredible submarine chasm in which the entire Himalayan chain could be sunk without showing a single pinnacle above the surface. He went back to the clipping. It was dated Manila, two years earlier. It was an obviously skeptical article on a report made by the crewmen of a sailing ship that stopped by Manila. Sailing ships are rare enough in modern times. This ship reported that she had sighted another of her own kind at sea. The two ships altered course to speak to each other. And the one which came into Manila declared that when the other vessel was no more than two miles away, white foam suddenly appeared on the sea just in front of her. A geyser of unsubstantial white stuff spouted up and spread, shooting up about thirty feet on the water. The bow of the other sailing ship entered the foam patch. And suddenly her bow tilted downward, her masts swayed forward, and the entire ship vanished into the white stuff, exactly as if she had sailed over a precipice. She did not sink. She dropped. She "fell" under water--under the foam--her sails still spread. One instant she sailed proudly. The next instant she was gone. The position of such an incredible happening was roughly given. It was almost exactly the same as the position written on the photograph of foam taken from the air. At the margin of the Luzon Deep. Terry found that his indignation had evaporated. The reason for it still remained, but now he wanted to know more about this happening and about the spheres of plastic with those deftly designed but enigmatic inclusions. The plastic objects had a purpose. He wanted to know what. And the news clipping.... Having announced crossly that he would ask to be set ashore as soon as the fish-driving unit was tested, he was ashamed to take it back. He stayed below, now angry at himself again. Nobody came below. Deirdre did not descend to cook. Night fell. Well after nightfall he heard movements on deck, and presently a voice which sounded oddly distant. The _Esperance's_ course changed abruptly. The quality of her motion altered once more. He went abovedecks. Twilight was long over, but the moon was not yet up. Here and there a wave-tip frothed, and blue luminescence appeared. Here and there a streak of dim blue light could be seen under water, where some fish darted. But those dartings were rare. Despite the yacht's shining wake and the curling wave-tips, the sea was darker than usual. Nick's voice came from aloft, faint and eerie and seeming to come from the stars. "... farther to port.... Two points ..."