I stopped short. "By Jove, now that you remind me of it, I promised to take them all out for a spin in the motor boat before luncheon. Hazzard has had his boat sent down."

She looked positively unhappy. "Oh, how I should love to get out for a spin on the river! I wonder if I'll ever be free to enjoy the things I like most of—"

"Listen!" I whispered suddenly, grasping her arm. "Did you hear footsteps in the—Sh!"

Some one was walking over the stone floor in the lower hall, brisk strides that rang out quite clearly as they drew nearer.

"It is—it is Mr. Pless," she whispered in a panic. "I recognise his tread. As if I could ever forget it! Oh, how I hate him! He—"

"Don't stop here to tell me about it," I cut in sharply. "Make haste! Get up to your rooms and lock yourself in. I'll—I'll stop him. How the deuce did he get into this side of the—"

"Through the dungeons. There is a passage," she, whispered, and then she was gone, flying noiselessly up the narrow stairway.

Assuming a nonchalance I certainly did not feel, I descended the stairs. We met in the broad hallway below. Mr. Pless approached slowly, evidently having checked his speed on hearing my footsteps on the stairs.

"Hello," I said agreeably. "How did you get in?"

He surveyed me coolly. "I know the castle from top to bottom, Mr. Smart. To be perfectly frank with you, I tried the secret panel in your study but found the opposite door blocked. You have no objection, I trust, to my looking over the castle? It is like home to me."