shop, Thorndyke halted. The shop
had been kept open late for the shoeing of a carriage horse, which was
just being led away, and the smith had come to the door for a breath of
air. Thorndyke accosted him genially.

"Good-evening. You are just the man I wanted to see. I have mislaid the
address of a friend of mine, who, I think, called on you this
afternoon--a lame gentleman who walks with a stick. I expect he wanted
you to pick a lock or make him a key."

"Oh, I remember him!" said the man. "Yes, he had lost his latchkey, and
wanted the lock picked before he could get into his house. Had to leave
his motor-car outside while he came here. But I took some keys round
with me, and fitted one to his latch."

He then directed us to a house at the end of a street close by, and,
having thanked him, we went off in high spirits.

"How did you know he had been there?" I asked.

"I didn't; but there was the mark of a stick and part of a left foot on
the soft earth inside the doorway, and the thing was inherently
probable, so I risked a false shot."

The house stood alone at the far end of a straggling street, and was
enclosed by a high wall, in which, on the side facing the street, was a
door and a wide carriage-gate. Advancing to the former, Thorndyke took
from his pocket the purloined key, and tried it in the lock. It fitted
perfectly, and when he had turned it and pushed open the door, we
entered a small courtyard. Crossing this, we came to the front door of
the house, the latch of which fortunately fitted the same key; and this
having been opened by Thorndyke, we trooped into the hall. Immediately
we heard the sound of an opening door above, and a reedy, nasal voice
sang out:

"Hello, there! Who's that below?"

The voice was followed by the appearance of a head projecting over the
baluster rail.

"You are Mr. Percy Haldean, I think," said the inspector.

At the mention of this name, the head was withdrawn, and a quick tread
was heard, accompanied by the tapping of a stick on the floor. We
started to ascend the stairs, the inspector leading, as the authorized
official; but we had only gone up a few steps, when a fierce, wiry
little man danced out on to the landing, with a thick stick in one
hand and a very large revolver in the other.

"Move another step, either of you," he shouted, pointing the weapon at
the inspector, "and I let fly; and mind you, when I shoot I hit."

[Illustration: THE STRANGER IS RUN TO EART