“SO,” said Freyberger, when this detailed description of the affair had been given to him by his Chief, “it is briefly this: Gyde was being blackmailed by this man; he called on him, murdered him, and cut off his head, put it in a bag, came to London with the bag and slipped out of his London house, carrying with him his jewels. It is an extraordinarily strange case.”

“It seems clear enough.”

“Not to me, sir—excuse me for saying so.”

The Chief of the Criminal Investigation Department had long had his eye on Freyberger. He recognized genius in the man. He knew his temperament also, and that, if given a full rein and let speak and act as he liked he blossomed; but, if snubbed or kept in check he wilted, and became just an ordinary detective.

“Just explain yourself,” he said. “Give me the points in your mind that strike you.”

“Well, sir,” said the other, “why did this man leave those utterly damning letters behind him on the mantelpiece?”

“You know as well as I do,” replied the Chief, “that in every criminal’s brain there is a black spot, a vacant point that betrays him, and leads him to do some act, some extraordinarily stupid act, which in turn leads him—here.”

“Quite so. Why did he cut off his victim’s head—what in the name of heaven did he want to burden himself with a human head for? The man was known in the neighbourhood, his body was there to be identified; taking the head away would seem to serve no known purpose, unless he intended to keep it as a curiosity or memento.”

“I confess it puzzles me,” replied the other.

“On top of these two puzzling facts,” went on Freyberger, “we have the death of Leloir the valet.”

“He may have opened the bag and come upon the head.”

“I have thought of that, but the explanation does not satisfy me, for, from the expression of his face—” Freyberger stopped.

“Yes?”

“Well, I am convinced he saw something worse than an ordinary human head.”

............