In the library, Locke, having persuaded Eva, left her and went down into the Graveyard of Genius, where he touched the secret spring and the massive door flew open. He entered the gloomy place and went at once to the shelf upon which lay the self-liberating diving-suit. He took the suit down and examined its every detail minutely. As he did so he became more and more enthusiastic and he could find no fault with any of its features.
"It's entirely practical," he exclaimed to himself. "I'm going to try it to-day."
He closed the great door and remounted the stairs, carrying the suit with him. But had he noticed the fiery eyes that had watched him through the secret rock door of the cavern he would not have been so eager to try the test he had in mind.
By this time Eva had called her car, and together Locke and Eva drove to the near-by cove, where there was a little launch which he planned to use.
Out into the river they sailed, Eva at the wheel, while Locke busied himself over the sputtering engine. Soon they arrived at a spot which was suitable for the test of the suit.
Locke had brought along the full equipment, and, while Eva took charge of the air-pump, Locke donned the diving-suit. Soon all was ready and Locke descended over the side, after carefully instructing Eva in each detail. Eva started pumping, while with her other hand she carefully paid out the air-line and signal-cord.
But in their close attention to the task in hand, neither had noticed a low, knifelike launch that had followed them and that was now hovering a short distance off.
Locke was now walking over the shell-strewn bottom, examining curious objects here and there. The tide was setting in strongly and at times it was with difficulty that he kept his feet.
He had become satisfied that this particular suit filled all the requirements of a first-class diving-suit, and he was about to try its special, self-liberating feature, when his attention was arrested by a vague mass which seemingly moved against the current.
This was so extraordinary that his first thought was of a shark. He stopped in his tracks and became motionless, for it is a well-known fact that these sea tigers rarely see an object unless it is in motion. Still, the vague form slowly took on more distinctness as in its course it gradually drew nearer to him. It was then that Locke was almost overcome with surprise. For there, groping his way toward him, was a diver, like himself.