A hall opened out from the conservatory, and on either side were rooms, variously furnished. He hurried on. Ahead, he saw a door which seemed to give upon the outer world. He grasped the knob. The door was locked, and the lock was one which a glance told him could be neither picked nor smashed.

Turning, he explored the rear of the house. In the east wing he found the kitchens and servants’ quarters, but a door which probably communicated with the kitchen gardens was locked.

Suddenly his wandering eyes caught the handle of a door in an angle of the pantry. He approached it and found that it opened upon a stair leading down. A gust of warm, damp air came up through the stairway, and for a moment Knight paused, sniffing curiously.

He found himself thinking of a certain sultry afternoon in India, when he had gone out into the simmering jungle. There was the same wild smell here—

He had his revolver in his hip pocket. That gave him confidence, and he must know if it would be possible for him to escape in this direction.

A phrase spoken by Ah Wing came to him—“Even in this house of hidden dangers!” But what dangers could there be?

Colonel Knight felt his way down into the basement. He found that it lay almost entirely below the level of the grounds, but presently his eyes became accustomed to the dusk and he could discern his surroundings.

He was in a broad and deep room, filled with a litter of packing cases, discarded articles of furniture, and a few garden tools. At its farther side was a door. Slowly and cautiously, the investigator made his way toward this.

It opened into a dark and narrow passage. He made his way along this, trying the handles of two locked doors, one on the right and the other on the left. Then he came to the end of the passage and to another door.

Cautiously, he opened it and looked inside: before him lay a room somewhat better lighted than the passage, but absolutely destitute of furniture. He crossed the threshold and stood for a long moment looking about him. The smell which he had associated with that hot afternoon in the jungle came to him almost overpoweringly now, but beyond he saw a door with an iron-barred transom. He wanted to try that door.