ass $250,000 worth of diamonds."

As La Croix was well known, details were useless.

The Bradys watched their quarry closely.

Knowing they had those diamonds with them, and that they would very likely
play a sharp trick to evade the inspectors, the Bradys were very careful.

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
attempt to speak to each one of the party in a friendly way at the table,
but they gave me such a cold reception, I had to withdraw in a hurry."

That day, La Croix and his party left Montreal.

Boarding a train for Toronto, they went away.

The Bradys were on the same train.

Once more their disguises were changed, for they did not want the smugglers
to see them in Toronto in the same characters, as it might arouse their
suspicions.

They were now rigged out as two regular army soldiers, and pretended to be
sightseeing, as most Americans are up in that region.

La Croix and his party only remained a day in Toronto.

The detectives now discovered that two of the spies had disappeared and a
swift search was made to find them.

Harry did the investigating.

He finally discov