The gust, turning to a gale, whistled at the loosely fitting doors. The flames of the candles became restless. The curtains rose and fell again, with melancholy motions. The hair of Lerne was blown about, white and feathery. The storm disordered those hairs, and brushed them this way and that, and whilst the spirit hand of the gale sported amongst the long hair, I, transfixed with amazement, bent over the bed, looking at something that appeared and disappeared under the silvery locks--_a purple scar, which encircled Lerne’s head from temple to temple_, the dreadful semi-crown which indicated the Circeean operation! My uncle had been operated on by whom? Otto Klotz, of course! Light had penetrated the mystery. Its last veil, a winding-sheet, had been torn. All was explained now--all! The sudden metamorphosis of the Professor, coinciding with the disappearance of the principal assistant, with Macbeth’s journey, and the eclipse of Lerne; all! The brutal letters, the changed handwriting--my failure to recognize him; the German accent, his failures of memory, and also the violent temper of Klotz--his rashness, and passion for Emma, and then his wicked activities and the crimes committed on Macbeth and on me! All! All!! All!!! Calling to mind Emma’s account, I was able to reconstitute the history of an unimaginable crime. Four years before my return to Fonval, Lerne and Otto Klotz returned from Nanthel, where they had passed the day. Lerne was probably in a happy mood. He was going once more to take up his noble studies in grafting, whose only aim was to relieve humanity. But Klotz, being in love with Emma, was hoping to divert those efforts to another object--one of profit--one of lucre--the exchange of brains: doubtless this very idea (which he was not able to carry out at Manheim for want of money), he had already proposed to my uncle, and without any result. But the assistant had his own Macchiavelian idea. With the help of his three compatriots, warned beforehand, and hidden in the thicket, he struck down the Professor, gagged him, and shut him up in the laboratory--this man, whose wealth and independence--in other words, whose personality--he invaded. * * * * * The next day, before dawn, he went back to the laboratory, where Lerne, who was being watched, awaited him. His three accomplices administered anesthetics to both, and placed the brain of Klotz in my uncle’s skull. As for the brain of Lerne, they no doubt contented themselves with placing it as best they might in the skull of Klotz, who was now only a dead body, and they buried it all in haste with the other _débris_. So there is Otto Klotz behind the mask, clothed in the appearance he desired, dressed like Lerne, master of Fonval, of Emma and the laboratory--a sort of monk of St. Bernard sheltered in the shell of the being whom he killed.