Go to bed, and to sleep if you can."

"As if we could," answered Miss Lorne agitatedly. "I shan't be able to close an eyelid. I'll try, of course, but

I know I shall not succeed. Come, uncle, come! Oh, do be careful, Mr. Narkom; and if that horrible man does come——"

"I'll have him, so help me God!" he vowed. "Switch off the light, and shut the door as you go out. This is 'Forty Faces.' Waterloo at last."

And in another moment the light snicked out, the door closed, and he was alone in the silent room.

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. The sound came, not from without the house, but from within, from the dark hall where he had stationed his men. 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."

"Happily, this one isn't. It's a modern innovation, not an ancient relic, that offers the means of entrance in this case. A Yankee occupied this house before I bought it from him, one of those blessed shivery individuals his country breeds, who can't stand a breath of cold air indoors after the passing of the autumn. The wretched man put one of those wretched American inflictions, a hot-air furnace, in the cellar, with huge pipes running to every room in the house, great tin monstrosities bigger round than a man's body, ending in openings in the wall, with what they call 'registers' to let the heat in or shut it out as they please. I didn't have the wretched contrivance removed or those blessed 'registers' plastered up. I simply had them papered over when the rooms were done up (there's one over there near that settee), and if a man got into this house, he could get into that furnace thing and hide in one of those flues until he got ready to crawl up it as easily as not. It struck me that perhaps it would be as well for you to examine that furnace and those flues before matters go any further."

"Of course it would. Great Scott! Sir Horace, why didn't you think to tell me of this thing before?" said Narkom excitedly. "The fellow may be in it at this minute. Come, show me the wretched thing."

"It's in the cellar. We shall have to go down the kitchen stairs, and I haven't a light."

"Here's one," said Petrie, unhitching a bull's-eye from his belt and putting it into Narkom's hand. "Better go with Sir Horace at once, sir. Leave the door of the gallery open and the light on. Fish and me will stand guard over the stuff till you come back, so in case the man is in one of them flues and tries to bolt out at this end, we can nab him before he can get to the windows."

"A good idea," commented Narkom. "Come on, Sir Horace. Is this the way?"

"Yes, but you'll have to tread carefully, and mind you don't fall over anything. A good deal of my paraphernalia—bottles, retorts, and the like—is stored in the little recess at the foot of the staircase, and my assistant is careless and leaves things lying about."

Evidently the caution was necessary, for a minute or so after they had disappeared behind the door leading to the kitchen stairway, Petrie and his colleagues heard a sound as of something being overturned and smashed, and laughed softly to themselves. Evidently, too, the danger of the furnace had been grossly exaggerated by Sir Horace, for when, a few

minutes later, the door opened and closed, and Narkom's men, glancing toward it, saw the figure of their chief reappear, it was plain that he was in no good temper. His features were knotted up into a scowl, and he swore audibly as he snapped the shutter over the bull's-eye and handed it back to Petrie.

"Nothing worth looking into, superintendent?"

"No, not a thing!" he replied. "The silly old josser! pulling me down there amongst the coals and rubbish for

an insane idea like that! Why, the flues wouldn't admit the passage of a child; and, even then, there's a bend, an abrupt 'elbow,' that nothing but a cat could crawl up. And that's a man who's an authority on the human brain! I sent the old silly back to bed by the way he came, and if——"

There he stopped, stopped short, and sucked in his breath with a sharp, wheezing sound. For, of a sudden, a swift pattering footfall and a glimmer of moving light had sprung into being and drawn his eyes upward. There, overhead, was Miss Lorne coming down the stairs from the upper floor in a state of nervous excitement, with a bedroom candle in her shaking hand, a loose gown flung on over her nightdress, and her hair streaming over her shoulders in glorious disarray.

He stood and looked at her, with ever-quickening breath, with ever-widening eyes, as though the beauty of her had wakened some dormant sense whose existence he had never suspected, as though, until now, he had never known how fair it was possible for a woman to be, how much to be desired. And whilst he was so looking she reached the foot of the staircase and came pantingly toward him.

"Oh, Mr. Narkom, what was it—that noise I heard?" she said in a tone of deepest agitation. "It sounded like a struggle, like the noise of something breaking, and I dressed as hastily as I could and came down. Did he come? Has he been here? Have you caught him? Oh! why don't you answer me, instead of staring at me like this? Can't you see how nervous, how frightened I am? Dear Heaven! will no one tell me what has happened?"

"Nothing has happened, Miss," answered Petrie, catching her eye as she flashed round on him. "You'd better go back to bed. Nobody's been here but Sir Horace. The noise you heard was me a-grabbing of him, and he and Mr. Narkom a-tumbling over something as they went down to look at the furnace."

"Furnace? What furnace? What are you talking