The duke glanced around, as if to make sure they were not watched, and then he covertly and quickly passed the tiny metal ball to Frank, who felt a strange thrill as he received it.

“Put it away at once,” whispered the Frenchman. “Do not tell a soul that you have it. Promise me you will not tell.”

Frank wondered at his readiness to accept the trust, and still more he wondered at the man’s willingness to trust him, a stranger. Still, he understood the remarkable position in which Laforce was placed. The man feared he might drop dead at any moment, and he did not wish the thing to be found upon him.

“What if you do not meet me here to-morrow to receive it back?” asked Merry.

“I shall be dead.”

“I know; but what shall I do with it then?”

“Keep it till the right one calls for it.”

“The right one?”

“Yes, Monsieur Merriwell.”

“How shall I know the right one?”