of it.” Holmes was outwardly calm, but his whole body gave a wriggle of suppressed excitement as he spoke. “By the way, Lestrade, who made this remarkable discovery?”
“It was the housekeeper, Mrs. Lexington, who drew the night constable’s attention to it.”
“Where was the night constable?”
“He remained on guard in the bedroom where the crime was committed, so as to see that nothing was touched.”
“But why didn’t the police see this mark yesterday?”
“Well, we had no particular reason to make a careful examination of the hall. Besides, it’s not in a very prominent place, as you see.”
“No, no—of course not. I suppose there is no doubt that the mark was there yesterday?”
Lestrade looked at Holmes as if he thought he was going out of his mind. I confess that I was myself surprised both at his hilarious manner and at his rather wild observation.
“I don’t know whether you think that McFarlane came out of gaol in the dead of the night in order to strengthen the evidence against himself,” said Lestrade. “I leave it to any expert in the world whether that is not the mark of his thumb.”
“It is unquestionably the mark of his thumb.”
“There, that’s enough,” said Lestrade. “I am a practical man, Mr. Holmes, and when I have got my evidence I come to my conclusions. If you have anything to say, you will find me writing my report in the sitting-room.”
Holmes had recovered his equanimity, though I still seemed to detect gleams of amusement in his expression.
“Dear me, this is a very sad development, Watson, is it not?” said he. “And yet there are singular points about it which hold out some hopes for our client.”
