Scarcely a move made by the family escaped them.

It soon became apparent to the detectives that an important move was soon
to be made, for the four spies were in frequent consultation with the
Frenchman and his family.

"They are evidently arranging a plan of action," Harry commented, as he and
his partner traced the men to La Croix's room for the fourth time.

"I wish there was some way of getting a clew to their design," Old King
Brady replied, in wistful tones. "We are completely in the dark."

"That's a sheer impossibility," Harry answered. "They are taking the most
extraordinary care not to let anyone hear a word they are saying or see a
thing they are doing. I've tried several times, and failed."

"We've got a sharp gang to deal with, my boy. And the worst of it is that
$250,000 worth of diamonds makes such a small package that they won't have
the slightest trouble to conceal it."

"As they are not likely to allow so valuable a parcel to leave their hands,
by arresting the whole gang the moment they reach the American side, we are
likely to find the jewels on the person of one or the other."

"And I quite agree with that plan," said Harry. "In fact, it's the only
safe method of securing them for a certainty."

"Have you noticed whether they made friends with any outsiders here?"

"No, they haven't. They keep strictly aloof from everybody. I made an