“There’s a half-sovereign for you,” my companion said, standing up and taking his hat. “I am afraid, Rance, that you will never rise in the force. That head of yours should be for use as well as ornament. You might have gained your sergeant’s stripes last night. The man whom you held in your hands is the man who holds the clue of this mystery, and whom we are seeking. There is no use of arguing about it now; I tell you that it is so. Come along, Doctor.”

We started off for the cab together, leaving our informant incredulous, but obviously uncomfortable.

“The blundering fool,” Holmes said, bitterly, as we drove back to our lodgings. “Just to think of his having such an incomparable bit of good luck, and not taking advantage of it.”

“I am rather in the dark still. It is true that the description of this man tallies with your idea of the second party in this mystery. But why should he come back to the house after leaving it? That is not the way of criminals.”