Captain Jack, making for the spiral stairway to the conning tower.

Just as the young skipper stepped out on deck he heard the “Hudson’s”
bow-gun break out sharply in the halting signal.

Taking a megaphone, Benson stood at the rail until the gunboat ranged up
alongside.

“Have you broken down?” came the hail from the gunboat’s bridge.

“I thought it best to stop speed, sir. We’ll have to look over our engines
before it will be safe to attempt any more speed work,” Captain Jack
answered. “I’ve caught a fellow tampering with our machinery. We hold him
a prisoner, now. Can you take him off our hands, sir?”

“One of _your own_ men?” came back the question.

“Of course, sir.”

“We’ll send a marine guard to take him, on your complaint, Mr. Benson.”

“Thank you, sir.”

The gunboat’s engines slowed down. Ere long her port side gangway was
lowered. Jack saw not only two marines and a corporal come down over the
side, but Lieutenant Commander Mayhew appeared in person. That officer
came over in the cutter.

“You’ve had treachery aboard, have you?” asked the lieutenant commander,
as he climbed up over the side.