"'After you went to bed?'
"'Yes.'
"'When did you go to bed?'
"'About eleven.'
"'So your son was gone at least two hours?'
"'Yes.'
"'Possibly four or five?'
"'Yes.'
"'What was he doing during that time?'
"'I do not know,' she answered, turning white to her very lips.
"Of course after that there was nothing more to be done. I found out where Lieutenant Charpentier was, took two officers with me, and arrested him. When I touched him on the shoulder and warned him to come quietly with us, he answered us as bold as brass, 'I suppose you are arresting me for being concerned in the death of that scoundrel Drebber,' he said. We had said nothing to him about it, so that his alluding to it had a most suspicious aspect."
"Very," said Holmes.
"He still carried the heavy stick which the mother described him as having with him when he followed Drebber. It was a stout oak cudgel."
"What is your theory, then?"
"Well, my theory is that he followed Drebber as far as the Brixton Road. When there, a fresh altercation arose between them, in the course of which Drebber received a blow from the stick, in the pit of the stomach, perhaps, which killed him without leaving any mark. The night was so wet that no one was about, so Charpentier dragged the body of his victim into the empty house. As to the candle, and the blood, and the writing on the wall, and the ring, they may all be so many tricks to throw the police on to the wrong scent."
"Well done!" said Holmes in an encouraging voice. "Really, Gregson, you are getting along. We shall make something of you yet."
"I flatter myself that I have managed it rather neatly," the detective answered proudly. "The young man volunteered a statement, in which he said that after following Drebber some time, the latter perceived him, and took a cab in order to get away from him. On his way home he met an old shipmate, and took a long walk with him. On being asked where this old shipmate lived, he was unable to give any satisfactory reply. I think the whole case fits together uncommonly well. What amuses me is to think of Lestrade, who had started off upon the wrong scent. I am afraid he won't make much of [15] Why, by Jove, here's the very man himself!"