“Sure; they never overlook them things.”

“Good; unbutton the front of your shirt, Fred.”

The two stared at the scar thus revealed, still incredulous, yet unable to refute the evidence of its existence.  Roberts touched it with his fingers to better assure himself of its reality.

“Darn it all,” he confessed.  “This beats hell.”

“It does,” coincided Westcott.  “This whole affair has been of that kind.  Now I’ll tell you where Tom Burke is—­he lies buried in the Cavendish family lot in Brooklyn.”

He turned to Colgate, who stood with mouth half open.

“You’re from New York; ever hear of the Cavendish murder?”

“Only saw a paragraph in the Chicago papers.  It wasn’t my case, and the only thing that interested me was that the name happened to be the same as assumed by the man I was following—­why?”

“Because this gentleman here is Frederick Cavendish, who was reported as killed—­struck down in his apartments on the night of April 16.  Instead he took the midnight flier West and you followed him.  The dead man was Tom Burke; wait a minute and I’ll tell you the story—­all I know of it, at least.”

He told it rapidly, yet omitting no detail of any interest.  The two detectives, already half convinced of their mistake, listened fascinated to the strange narrative; it was a tale of crime peculiarly attractive to their minds; they could picture each scene in all its colours of reality.  As the speaker ended, Roberts drew in his breath sharply.

“But who slugged Burke?” he asked.  “The fellow went in there after swag; but who got him?”

“That is the one question I can’t answer,” replied Westcott gravely, “and neither can Fred. It doesn’t seem to accord with the rest of our theories.  Enright told Lacy he didn’t know who the dead man was, or who killed him.”

Miss Donovan pushed her way in front of Cavendish, and faced the others, her cheeks flushed with excitement, a paper clasped in one hand.

“Perhaps I can help clear that up,” she said clearly.  “This is the letter found under Miss La Rue’s bed.  I have read part of it.  It was written by Jack Cavendish just as he was taking a boat for South America.  It is not a confession,” she explained, her eyes searching their faces, “just a frightened boy’s letter.  I wouldn’t understand it at all if I didn’t know so much about the case.  What it seems to make clear is this:  The La Rue girl and Patrick Enright schemed to get possession of the Cavendish property through her marriage to John; this part of the programme worked out fairly well, but John could not get hold of enough money to satisfy them.

“Enright and the girl decided to put Frederick out of the way, but lacked the nerve to commit murder—­at least in New York.  Their scheme seems to have been to inveigle their victim away from the city, and then help him to get killed through an accident.  In that case the law would award the entire estate to John.  They never told John this plan, but their constant demands for money fairly drove the young man to desperation.