For reply, I ran up to the door and thrust my fist through the canvas, ripping it away from its clumsy tacking.

"Who's in there?" I cried. "Answer me!"

Dead silence; then a click as Worth snapped on a flood of light from his pocket torch, saying tolerantly, tiredly,

"I told you there was no one. There couldn't be."

"I tell you, Worth, there was. I saw the shadow on the square of that canvas. Give me the torch."

I pushed the flashlight through the opening and played the light cone about the room in a quick survey; then brought the circle of white glow to rest upon one of the side walls; and my hand went down and back to grip fingers about the butt of my revolver. There was, as Worth had said, but one other door to this room; but more, there was apparently no other exit; no windows, no breaks in the walls. My circle of light was on this second door; and the very heart of that circle was a heavy steel bolt on the door, the bar of which was firmly shot into the socket on the frame. The only exit from that room, other than the door through which I now leaned with pistol raised, was locked—bolted from the inside!

Worth was crowding his big frame into the opening beside me.

"Keep back," I growled. "Some one's inside," and I sent the light shaft into corners to drive out the shadows, to cut in under the desk and chairs. Worth's reply was a laugh, and his arm went by me to reach inside the door. Then, as his fingers found the button, a light sprang out from a lamp upon the center desk.

"You're letting your nerves play the deuce with you, Jerry," he said lightly. "Make way for my crowbar and we'll get in out of the wet."

I made no answer, but for a long moment more I searched that room with my eyes; but it was the kind you see all over at a glance. Big, square, plain, it hadn't a window in it; the walls, lined with book shelves, floor to ceiling; a fireplace; a library table with drawers; a few chairs. No chance for a hideout. I glanced at the ceiling and confirmed the evidence of my eyes. There was a skylight, and through it had come that curious glow that first attracted my attention to the place.