Elk swore softly but savagely.

“That was it!” he said. “He was the ‘policeman’ who was spiriting Hagn away under the pretence of arresting him! And if one of my men had not taken his prisoner from him they would both have escaped. Wait!”

He went in search of the detective who had brought in Hagn.

“I don’t know the constable,” said that officer. “This is a strange division to me. He was a tallish man with a heavy black moustache. If it was a disguise, it was perfect, sir.”

Elk returned to report and question. But again Mr. Broad’s explanation was a simple one.

“I tell you that the Frogs were openly enjoying the joke. I heard one say that the ‘rozzer’ got away—and another refer to the escaped man as a ‘flattie’—both, I believe, are cant terms for policemen?”

Elk nodded.

“What is your interest in the Frogs, Broad?” he asked bluntly. “Forget for the minute that you’re a parlour-criminologist and imagine that you’re writin’ the true story of your life.”

Broad considered for a while, examining the cigar he had been smoking.

“The Frogs mean nothing to me—the Frog everything.” The American puffed a ring of smoke into the air and watched it dissolve.