“Oh, yes,” resumed Burke.  “Of course I sent copies of the finger-prints to Scotland Yard.  Within two weeks they replied that one set belonged to William Forbes, a noted counterfeiter, who, they understood, had sailed for South Africa but had never arrived there.  They were glad to learn that he was in America, and advised me to look after him sharply.  The woman was also a noted character—­Harriet Wollstone, an adventuress.”

“I suppose you have shadowed them ever since?” Kennedy asked.

“Yes, a few days after they were arrested the man had an accident with his car.  It was said he was cranking the engine and that it kicked back and splintered the bone in his forearm.  Anyhow, he went about with his hand and arm in a sling.”

“And then?”

“They gave my man the slip that night in their fast touring-car.  You know automobiles have about made shadowing impossible in these days.  The house was closed up, and it was said by the neighbours that Williams and Mrs. Williams—­as they called themselves—­had gone to visit a specialist in Philadelphia.  Still, as they had a year’s lease on the house, I detailed a man to watch it more or less all the time.  They went to Philadelphia all right; some of the bills turned up there.  But we saw nothing of them.

“A short time ago, word came to me that the house was open again.  It wasn’t two hours later that the telephone rang like mad.  A Fifth Avenue jeweller had just sold a rope of pearls to an Englishwoman who paid for it herself in crisp new one-hundred-dollar bills.  The bank had returned them to him that very afternoon—­counterfeits.  I didn’t lose any time making a second arrest up at the house of mystery at Riverwood.  I had the county authorities hold them—­and, now, O’Connor, tell the rest of it.  You took the finger-prints up there.”

O’Connor cleared his throat as if something stuck in it, in the telling.  “The Riverwood authorities refused to hold them,” he said with evident chagrin.  “As soon as I heard of the arrest I started up myself with the finger-print records to help Burke.  It was the same man, all right—­I’ll swear to that on a stack of Bibles.  So will Burke.  I’ll never forget that snub nose—­the concave nose, the nose being the first point of identification in the ’portrait parle.’  And the ears, too—­oh, it was the same man, all right.  But when we produced the London finger-prints which tallied with the New York fingerprints which we had made—­believe it or not, but it is a fact, the Riverwood finger-prints did not tally at all.”

He laid the prints on the table.  Kennedy examined them closely.  His face clouded.  It was quite evident that he was stumped, and he said so.  “There are some points of agreement,” he remarked, “but more points of difference.  Any points of difference are usually considered fatal to the finger-print theory.”

“We had to let the man go,” concluded Burke.  “We could have held the woman, but we let her go, too, because she was not the principal in the case.  My men are shadowing the house now and have been ever since then.  But the next day after the last arrest, a man from New York, who looked like a doctor, made a visit.  The secret-service man on the job didn’t dare leave the house to follow him, but as he never came again perhaps it doesn’t matter.  Since then the house has been closed.”