For ten or a dozen minutes not even the bare suggestion of a noise disturbed the absolute stillness; then of a sudden, his trained ear caught a faint sound that made him suck in his breath and rise on his elbow, the better to listen--a sound which came, not without the house, but from within, from the dark hall where he had stationed his men, to be exact. As he listened he was conscious that some living creature had approached the door, touched the handle, and by the swift, low rustle and the sound of hard breathing, that it had been pounced upon and seized. He scrambled out from beneath the table, snicked on the light, whirled open the door, and was in time to hear the irritable voice of Sir Horace say, testily: "Don't make an ass of yourself by your over-zealousness. I've only come down to have a word with Mr. Narkom," and to see him standing on the threshold, grotesque in a baggy suit of striped pyjamas, with one wrist enclosed as in a steel band by the gripped fingers of Petrie. "Why didn't you say it was you, sir?" exclaimed that crestfallen individual, as the flashing light made manifest his mistake. "When I heard you first, and see you come up out of that back passage, I made sure it was him; and if you'd a struggled, I'd have bashed your head as sure as eggs." "Thank you for nothing," he responded testily. "You might have remembered, however, that the man's first got to get into the place before he can come downstairs. Mr. Narkom," turning to the superintendent, "I was just getting into bed when I thought of something I'd neglected to tell you; and as my niece is sitting in her room with the door open, and I wasn't anxious to parade myself before her in my night clothes, I came down by the back staircase. I don't know how in the world I came to overlook it, but I think you ought to know that there's a way of getting into the picture gallery without using either the windows or the stairs, and that way ought to be both searched and guarded." "Where is it? What is it? Why in the world didn't you tell me in the first place?" exclaimed Narkom irritably, as he glanced round the place searchingly. "Is it a panel? a secret door? or what? This is an old house, and old houses are sometimes a very nest of such things."