"By chance," Monsieur Dupont replied.

"Did you know Copplestone before?"

"I did not. I had never seen him. I came with my friend, Tranter."

"You were here all the evening?"

"Yes."

"Anything to tell me?" the inspector asked, looking at him intently.

Monsieur Dupont smiled.

"Only, my friend, that I imagine you will find it an interesting and somewhat unusual case."

"That's not enough—from you," the inspector retorted.

"If I may be permitted to advise—it is a case in which you would do well to ignore the obvious."