Chapter 22: The Second Letter from Irene

The safe house smelled of someone else's cooking — boiled mutton, Watson thought, and the particular damp of a building that had been closed for weeks before being hastily reopened. It was a narrow terraced house in Kennington, three floors, unremarkable in every particular, the kind of house that existed in its thousands across South London and drew precisely no one's attention. Lestrade had given him the address on a scrap of paper in the street, spoken the name of the landlady — Mrs. Garrett, retired, asked no questions for the right weekly rate — and then disappeared into the dark with his constables. Perkins had come as far as the corner, examined the house with the professional scepticism of a man who has slept in worse, and agreed to take the back room on the first floor.

Watson had taken the front room on the second.

It was after one in the morning when he found the letter.