tampering with the lock on the door of the forward compartment.
What's in there?"

"Nothing but the gasoline tank. I keep the bulkhead sliding door
locked on general principles. I can't imagine what the fellow
would want to open it for. There's nothing of value in there.
Perhaps he isn't right in his head. Was he a tramp?"

"No, he was well dressed but he seemed very nervous during the
auction, as if he was disappointed not to have secured the boat.
Yet what could he want in that compartment? Have you the key to
the lock, Mr. Hastings?"

"Yes, it belongs to you now, Mr. Swift," and the former owner
handed it to Tom, who quickly unlocked the compartment. He slid
back the door and peered within, but all he saw was the big
galvanized tank.

"Nothing in there he could want," commented the former owner of
the craft.

"No," agreed Tom in a low voice. "I don't see what he wanted to
open the door for." But the time was to come, and not far off,
when Tom was to discover quite a mystery connected with the
forward compartment of his boat, and the solution of it was fated
to bring him into no little danger.

"It certainly is odd," went on Mr. Hastings when, after Tom had
secured the screw driver from his motor-cycle tool bag, he aided
the lad in removing the letters from the bow of the boat "Are you