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 discovered that one of them had gone to get married, and the other acted as best man at the ceremony. The spy married a pretty French-Canadian girl. His companion returned to La Croix's party and the bride and groom started off on a short wedding trip. Young King Brady dropped them. "They'll be so busy spooning and lally-gagging that he won't have any time to attend to this smuggling game," thought the boy detective, as he went back to his partner to report the occurrence. Old King Brady was watching the Frenchman's party. Next day the smugglers boarded the cars for Niagara, and the Bradys felt that their work would soon be at an end. As the Custom House officers of Niagara had been specially warned against these people, they made a very careful search of their baggage and persons.