“Yes; one of my natural enemies, or, shall I say, my natural prey. Briefly, Watson, I am in the midst of a very remarkable inquiry, and I have hoped to find a clue in the incoherent ramblings of these sots, as I have done before now. Had I been recognised in that den my life would not have been worth an hour's purchase; for I have used it before now for my own purposes, and the rascally Lascar who runs it has sworn to have vengeance upon me. There is a trap-door at the back of that building, near the corner of Paul's Wharf, which could tell some strange tales of what has passed through it upon the moonless nights.”