“Then I went over to the butcher’s in the Strand to get a bit of steak.”

“And saw nothing more of her?”

“Yes, sir. I did see her again. As I was coming back I met her in the Strand, at the corner of Arundel Street, walking with a gentleman who looked like a City man. She said something to him, and he turned and had a good look at me.”

“Then it must have been this same woman who was in my chambers here when I returned,” I said.

“A woman here?” she ejaculated.

“Yes; when I entered there was a woman here, and she escaped as though she were a thief. She must have gone out and rejoined the man, who was awaiting her somewhere in the vicinity. That would bear out the fact that you encountered her again.”

“But how could she get in? I’m always careful to see that the door is properly closed.”

“Probably she stole the extra latch-key while prying about the place. See whether it is still on the nail.” She crossed the room, and next moment gasped—“It’s gone, sir!”

“Ah!” I said. “Just as I thought! The story she told you was a mere excuse to obtain admittance to the place, and, if possible, to get possession of the key. This she obtained, and, having watched you out, returned and continued her search for something she desired to secure. We must at once examine the whole place, and seek to discover what’s been stolen.”

“Do you think she was a common thief, sir?” inquired Parker, dumbfounded by the ingenuity with which the latch-key had been secured.