“The ignition power was lowered, and that may have been the most that the
fellow did,” said Hal. “Yet, at the same time, before putting these
engines to any severe test, I believe they ought to be cooled and looked
over.”

Lieutenant Commander Mayhew frowned.

“These delays eat up our practice cruise time a whole lot,” he grumbled.

“I’ll put the engines through their paces, and chance mischief having been
done to them, if you wish, sir.”

“No; that won’t do either, Mr. Hastings,” replied the naval officer. “This
craft is private property, and I have no right to give orders that may
damage private property. I’ll hold the fleet until you’ve had time to
inspect your engines properly. By that time, however, we’ll have to put
back to the coast for the night, for our practice time will be gone.”

“In the days to follow, sir,” put in Benson, earnestly, “I think we can
more than make up for this delay. We won’t have the traitor aboard after
this.”

“What earthly object can the fellow have had for wanting to damage your
motors?” demanded the naval officer, looking hopelessly puzzled.

“I can’t even make a sane guess, sir,” Jack Benson admitted.

An hour and a half later the “Hudson” and the two submarines headed back
for a safe little bay on the coast. Here the three craft anchored for the