“Perhaps not; but it’s our duty to be on guard. If anything happened to Dr. Perkins’ invention now it would be almost impossible to repair it in time for the tests he wants to make.”
Talking thus the two lads got into their clothes, drank some coffee, which Frank had prepared while they were dressing, and then set out into the night. They made for the cove from which Harry had started his eventful swim.
“Best wait here till they come round,” said Frank, and he and Billy found places in the sand and made themselves as comfortable as possible till they should hear the footsteps of one of the young sentries. They had not long to wait. Hardly fifteen minutes had elapsed before Frank’s sharp ears caught the sound of some one approaching. A minute later Pudge joined them. His first words were not calculated to make the newcomers feel at ease.
“Where’s Harry?” he demanded.
“Don’t you know?” ejaculated Frank with considerable surprise.
“No. I’ve been making my patrol regularly, and the last three times I’ve been round I haven’t met him.”
Frank’s face could only be dimly seen in the darkness, but all his alarm was plain enough in his next words.
“What can have become of him?”
“Maybe he took the dinghy and decided to look over the motor boat and the hulk,” suggested Billy.
“That’s easy enough to find out,” declared Frank, starting for the place where the dinghy had been beached. A moment later he stumbled over the anchor and, closely following this, by the aid of a lighted match, he made the discovery that the rope had been slashed.