On quitting the singular Oriental club, Harley had first raced off to a public telephone, where he had spoken for some time—as I now divined—to Scotland Yard. For when we presently arrived at the headquarters of the Metropolitan Police, I was surprised to find Inspector Wessex awaiting us. Leaning out of the cab window:  
“Yes?” called Harley excitedly. “Was I right?”
 
“You were, Mr. Harley,” answered Wessex, who seemed to be no less excited than my companion. “I got the man's reply an hour ago.”
 
“I knew it!” said Harley shortly. “Get in, Wessex; we haven't a minute to waste.”
 
The Inspector joined us in the cab, having first given instructions to the chauffeur. As we set out once more:
 
“You have had very little time to make the necessary arrangements,” continued my friend.
 
“Time enough,” replied Wessex. “They will not be expecting us.”
 
“I'm not so sure of it. One of the biggest villains in the civilized world recognized me three minutes before I called you up and then made good his escape. However, there is at least a fighting chance.”
 
Little more was said from that moment until the end of the drive, both my companions seeming to be consumed by an intense eagerness to reach our destination. At last the cab drew up in a deserted street. I had rather lost my bearings; but I knew that we were once more somewhere in the Chinatown area, and:
 
“Follow us until we get into the house,” Harley said to Inspector Wessex, “and wait out of sight. If you hear me blow this whistle, bring up the men you have posted—as quick as you like! But make it your particular business to see that no one gets out!”
 
Into a pitch-dark yard we turned, and I felt a shudder of apprehension upon observing that it was the entrance to a wharf. Dully gleaming in the moonlight, the Thames, that grave of many a ghastly secret, flowed beneath us. Emerging from the shadow of the archway, we paused before a door in the wall on our left.
 
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 g............