"Have you explored the island thoroughly?" asked Merritt under his breath. Somehow the dim hour and the situation seemed to preclude the idea of loud talking.
"Of course not. Not yet," breathed the other in the same tones. "We will break the news to the rest of the Patrol after breakfast. It's no use alarming them yet."
"It isn't possible that he went off on an early fishing expedition?"
For answer, Rob waved his hand toward the water, where the Flying Fish lay rocking gently at her anchor. Ashore the dingy lay as Merritt and his companions had left it the night before.
"But what can have happened to him?" burst out Merritt, as they made their way over to Ernest Thompson's side.
"I cannot think. It is absolutely mystifying. I am going to start for the captain's place now. He may be able to throw some light on the affair."
Merritt shook his head.
"Hardly likely. If there is no trace of Joe Digby on this side of the island, it is improbable that Captain Hudgins knows anything about him."
"Well," rejoined Rob in a troubled voice, "we've got to try everything. I am responsible for his safe keeping while he is in camp. I blame myself for allowing the kid to go on sentry duty at all."
"No use doing that," comforted Merritt; "there's one thing sure, he can't have melted away. He must be somewhere on the island. There are no wild beasts or anything like that here to carry him off, so if we keep up the search we must come upon him sooner or later."