She went below, and instants later was up again.
"I have a feeling," she said, "that something interesting is going to happen. I'll be back."
She swung lightly to the wharf and headed for land. Terry went below, to find his breakfast laid out on the cabin table. He settled down to it, but first pulled a book from the shelves. It was a volume on oceanography, and its pages showed that it had often been referred to. He found the Luzon Deep described. Its area was relatively small, a mere ninety-mile-long chasm in the sea-bed. But it was second only to the Mindanao Deep in its soundings, and a close second at that. Its maximum depth was measured at twenty-seven thousand feet. Over five miles. There was a mention of Thrawn Island as being on the very edge of the Deep. According to the book, the island was the peak of one of the most precipitous and tallest submarine mountains in the world. Three miles from where Thrawn Island lay, there were soundings of twenty-eight thousand feet and upward. This depth extended as a trench....
The staccato roaring of an outboard motor sounded some distance away. It bellowed toward the yacht, swung about, and cut off. Terry gulped down his coffee and went abovedecks, just as Deirdre was fastening the small craft alongside the yacht.
"Taxi?" she asked amiably. "I got the boat. Where to?"
Terry swung down and took the steering grip. He headed the boat away. There was a box for bait, a few fishing lines, and even two highly professional fish-spears on board. Fishing was not necessarily a sedentary pastime here.
"We try the lagoon entrance," he said. "I've an idea. I noticed something last night, when we came in."
"Do you want to brief me?"
"I'd rather not," he admitted.
Deirdre shrugged without resentment. The little craft went sturdily toward the passageway to the open sea. She formed an arrowhead of waves as she moved. She neared the points of land at the ends of the coral formation enclosing the lagoon. Thrawn Island was not an atoll. But the beaches were made of snow-white coral sand. Outside there was clear water for a space and then a reef on which the seas broke.