“Good gracious, Mr. Holmes, do you mean to tell me that, all the time I was talking to Bannister in this room, we had the man prisoner if we had only known it?”
“So I read it.”
“Surely there is another alternative, Mr. Holmes. I don’t know whether you observed my bedroom window?”
“Lattice-paned, lead framework, three separate windows, one swinging on hinge, and large enough to admit a man.”
“Exactly. And it looks out on an angle of the courtyard so as to be partly invisible. The man might have effected his entrance there, left traces as he passed through the bedroom, and finally, finding the door open, have escaped that way.”
Holmes shook his head impatiently.
“Let us be practical,” said he. “I understand you to say that there are three students who use this stair, and are in the habit of passing your door?”
“Yes, there are.”
“And they are all in for this examination?”
“Yes.”