d in the office, and described how Mlle. Nadiboff had walked
out with him.

"So the little minx was hinting at more mischief to come, was she?"
demanded the shipbuilder. "Jack, I believe she's equal to it. Her
crowd are anyway, if it's true that Gaston, from his cell in jail, could
plan the attempt to blow the 'Benson' last night."

Hal, too, soon came up and heard. He turned anxious gaze upon his chum.

"Jack, old fellow," he pleaded, "I know you're not much given to being
afraid of things. But, at least, look out for yourself a bit. Be more
prudent than you usually are about yourself. That crowd of foreign
spies, having failed and having brought themselves into trouble, mean
to have revenge. Any of us are liable, but you'll be the shining
mark of all to be picked out."

"There can't be many more of that crowd left at large," laughed Jack,
lightly.

"I wonder why the Secret Service men don't arrest Lemaire and the
Nadiboff young woman?" asked Mr. Pollard, the last to rejoin the little
group.

"Trotter and Packwood must have some good reasons of their own," Jack
replied, thoughtfully. "For one thing, they hardly have any evidence
that they could use against the pair."

"They could at least drive them from Spruce Beach," retorted the inventor.

"Perhaps the Secret Service man are giving the pair enough rope for their
hanging," proposed Jack.

At that moment the two detectives were espied going past in a buggy.
They waved their hands to the party. Jack replied by a signal to halt.
He and Hal ran down to the road to speak to the detectives.

"If it's a fair question to ask," demanded Hal, "what are you going to
do with Lemaire and Mlle. Nadiboff?"

"To tell you the truth, we don't know," Trotter answered. "We haven't
anything we could very well fasten on them. But of this you may be
sure; our various moves are known to them, and they're on the
tenterhooks of anxiety wondering what's going to break loose next. More
than that, both are sharp enough to have guessed that it would be
impossible for either of them to get away from Spruce Beach, now, without
our leave. But we'll have to leave you, now, boys. You've been of so
much help to us that I don't mind telling you what we're up to at this
moment. We're driving back to jail, and we're going to try to put the
screws on Leroux and his Greek companion. If we can make 'em think
we've gained new evidence against 'em, they may get scared and begin
to