“But—I—er—is that door closed?” he asked of the ugly little man as he glanced suspiciously behind him.

The Doctor rose and latched it. Then he resumed his seat.

“The fact is, I came down here to-day for two reasons—to see little Aggie and also to make some inquiries.”

“Inquiries!” echoed Diamond. “What about?”

“About something that concerns you,” was “Red Mullet’s” reply. “About certain papers which belonged to a man named Blanc, who died in a little hotel opposite the Gare du Nord.”

“I—I don’t understand you. What do you mean?” asked Diamond, with a perceptible start.

“Come, my dear Doc, you may just as well be frank and open with me. You know the kind of man I am. You’ve got hold of papers which don’t belong to you—and well, all praise to you, I say, if they’re worth anything. I don’t see why you shouldn’t deal with a dead man’s property if he deliberately wished to destroy it.”

“How do you know all this, Mr Mullet?” asked the Doctor, his face pale and much surprised.

“Well, my source of information don’t matter very much, does it?” remarked the other, stretching out his long legs to the warmth of the fire. “But I can tell you it’s lucky for you and your friends that I’ve found out about it—or—well, I can only tell you something would have happened—something very unfortunate.”

“I don’t follow you.”