The Clue of the Silver Key by Edgar Wallace

The trailer lost his quarry in Oxford Street and wandered disconsolately onward. A sort of homing instinct led him towards Regent's Park. Naylors Crescent was a magnificent little side street leading from the outer circle. It was very silent, its small, but stately, houses were in darkness.

Mr Tickler--such was his peculiar name--stopped before No. 17 and looked up at the window. The white blinds were drawn down and the house was lifeless. He stood, with his hands thrust into his pockets, blinking at the green door that he knew so well, at the three worn steps leading down, and the hollow steel railway that masons had fixed into the stonework to allow the easy descent of an invalid chair.