At that moment something gleamed through the air, whizzed past my ear, and fell with a metallic jingle on the stones!

Instinctively we both looked up.

At an unlighted window on the first floor I caught a fleeting glimpse of a dark face.

“You were right!” I said.  “Ali of Cairo has forestalled us!”

Harley stooped and picked up a knife with a broad and very curious blade.  He slipped it into his pocket, nonchalantly.

“All evidence!” he said.  “Keep in the shadow and bend down.  I am going to stand on your shoulders and get into that window!”

Wondering at his daring, I nevertheless obeyed; and Harley succeeded, although not without difficulty, in achieving his purpose.  A moment after he had disappeared in the blackness of the room above.

“Stand clear, Knox!” I heard.

Two of the cushion seats sometimes called “poof-ottomans” were thrown down, and: 

“Up you come!” called Harley.  “I’ll grasp your hands if you can reach.”

It proved no easy task, but I finally managed to scramble up beside my friend—­to find myself in a dark and stuffy little room.

“This way!” said Harley rapidly—­“upstairs.”

He led the way without more ado, but it was with serious misgivings that I stumbled up a darkened stair in the rear of my greatly daring friend.

A pistol cracked in the darkness—­and my fez was no longer on my head!

Harley’s repeater answered, and we stumbled through a heavily curtained door into a heated room, the air of which was laden with some Eastern perfume.  In the dim light from a silken-shaded lantern a figure showed, momentarily, darting across the place before us.

Again Harley’s pistol spoke, but, as it seemed, ineffectively.

I had little enough opportunity to survey my surroundings; yet even in those brief, breathless moments I saw enough of the place wherein we stood to make me doubt the evidence of my senses!  Outside, I knew, lay a dingy wharf, amid a maze of mean streets; here was an opulently furnished apartment with a strong Oriental note in the decorations!

Snatching an electric torch from his pocket, Harley leaped through a doorway draped with rich Persian tapestry, and I came close on his heels.  Outside was darkness.  A strong draught met us; and, passing along a carpeted corridor, we never halted until we came to a room filled with the weirdest odds and ends, apparently collected from every quarter of the globe.

Crack!

A bullet flattened itself on the wall behind us!

“Good job he can’t shoot straight!” rapped Harley.

The ray of the torch suddenly picked out the head and shoulders of a man who was descending through a trap in the floor!  Ere we had time to shoot he was gone!  I saw his brown fingers relax their hold—­and a bundle which he had evidently hoped to take with him was left lying upon the floor.