Coming out into the corridor, he consulted his watch. Then he glanced in the direction of the room which held the two men he had cause to fear--such ample cause as he little dreamed of at that moment. To make assurance doubly sure, he walked that way, not secretly, but boldly, since it was part of his project now to court observation--by others, at any rate, if not by the drugged emissaries of Scotland Yard. He waited outside the closed door and heard what he expected to hear, the snoring of two men sound asleep. Returning, he did not reenter his own room, but crossed the head of the staircase to Robert's. He knocked lightly, and his brother's "Hello, there! Come in!" reached Furneaux's ears. Not a word of the remainder of the colloquy that ensued was lost on either of the detectives. "Sorry to disturb you, Bob," said Hilton, speaking from the doorway, "but I thought you might not be in bed, and I've come to tell you that Sylvia has just gone out by way of the drawing-room and is wandering about the park." "Sylvia! On her lonesome?" was Robert's astounded cry. "Yes. It isn't right. I can't understand her behavior. I would have followed her myself; but in view of your statement at dinner tonight, I fancied it would save some annoyance if I entrusted that duty to you." "Look here, Hilton, old chap, are you really in earnest?" "About Sylvia? Yes. I actually saw her. At this moment she is heading for the lake. If you hurry you'll see her yourself." "I say, it's awfully decent of you ... I take back a lot of what I said tonight.... Of course, as matters stand, this is _my_ job.... Tell MacBain not to lock us out." "I'll attend to that, if necessary. But don't mention me to Sylvia. She might resent the notion of being spied on. Say that you, too, were strolling about. You see, I heard the window being opened, and looked out, naturally. Anyhow, drop me, and run this affair on your own." Robert was slightly obfuscated--the fresh air quickly made him worse--but he was sensible of having grossly misjudged Hilton. "Right-O," he said, hurrying downstairs. "We'll have a talk in the mornin'. Dash it! It's twelve o'clock. That silly kid! What's she after, I'd like to know?" Robert gone, Hilton returned to his own room and rang a bell. MacBain came, and was asked if he was aware that Miss Sylvia had quitted the house. MacBain gave his version of the story, and Fenley remarked that he might leave the window unfastened until he made his rounds at one o'clock. Seemingly as an afterthought, Hilton mentioned his brother's open door, and MacBain discovered that Mr. Robert was missing also.