Klein, the victim of Gyde, had made a bust of his assassin.

Upon the body of Müller was found the copy of an old blackmailing letter addressed to Lefarge.

In the room where Klein was found dead was found a copy of a blackmailing letter addressed to Gyde.

Upon each of the murdered men’s chests were tattooed initials, exactly in the same place, over the second right costal cartilage.

A strange similarity bound the two cases together, but the strangest thing drawing the two cases together was the fact, the almost certain fact, that Müller and Klein were one and the same person.

The fact that both men were artists of a high type, that both men were blackmailers, that both men kept copies of old blackmailing letters in their own handwriting—a most extraordinary blunder to commit—that both men were decapitated in exactly the same manner, and that each man had tattooed, in exactly the same place on his breast, his own initials, all these facts crowned by the master fact that Klein had left behind him, in his rooms in Howland Street, a portrait of himself with the name “Müller” partly erased from the back. All these facts, I repeat, made it quite clear to the mind of Freyberger that Klein and Müller were one and the same person. If this was so, Lefarge could not have murdered Müller, yet a frightful avalanche of evidence condemned him.

The evidence admitted of no cavil. No one else could have committed the crime. The assassination of Müller by Lefarge was even more conclusively proved than the assassination of Klein by Sir Anthony Gyde; for in the cottage on the fells another person might conceivably have been hidden at the time of the murder, but in the room in the Rue de Turbigo the evidence conclusively proved that no one could have been there at the critical moment but Lefarge and Müller.

The two cases, then, were connected together by many threads. At first sight the fact of this intimate connexion between the Lefarge and the Gyde case might seem to plunge the Gyde case into more profound darkness, to heap perplexity on perplexity.

But to Freyberger the discovery of this connexion was a huge step gained. Having verified the similarity of the incidents in the two cases he did not bother about them for a moment, cast them aside, took a broad view of the whole business and arrived at the grand conclusion that the active criminal agent in the Lefarge case was also the active criminal agent in the Gyde case.

“Now, if this is so,” argued Freyberger, “there are only four men to pick our criminal agent from. He must be either Lefarge, Müller, Klein or Gyde.