"Here is a rough chart of the place."
"Opening the door, I started down the corridor to find out. There was a straight passage dimly lit which led from the room in which in which I had been working, and was the only exit from it. It ended in a curving staircase, with the commissionaire's lodge in the passage at the bottom. Halfway down this staircase is a small landing, with another passage running into it at right angles. The second one leads, by means of a second small stair, to a side-door used by servants, and also as a short cut by clerks when coming from Charles Street."
"Then we returned to the office, and searched the stairs and the passage without result. The corridor which led to the room was laid down with a kind of creamy linoleum, which shows an impression very easily."