“Hullo!” cried Smith, who was leading—­“what now?”

We had crept along the crown of a sloping roof and were confronted by the blank wall of a building which rose a story higher than that adjoining it.  It was crowned by an iron railing, showing blackly against the sky.  I paused, breathing heavily, and seated astride that dizzy perch.  Weymouth was immediately behind me, and—­

“It’s the Cafe de l’Egypte, Mr. Smith!” he said, “If you’ll look up, you’ll see the reflection of the lights shining through the glass roof.”

Vaguely I discerned Nayland Smith rising to his feet.

“Be careful!” I said.  “For God’s sake don’t slip!”

“Take my hand,” he snapped energetically.

I stretched forward and grasped his hand.  As I did so, he slid down the slope on the right, away from the street, and hung perilously for a moment over the very cul de sac upon which the secret door opened.

“Good!” he muttered “There is, as I had hoped, a window lighting the top of the staircase.  Ssh!—­ssh!”

His grip upon my hand tightened; and there aloft, above the teemful streets of Soho, I sat listening ... whilst very faint and muffled footsteps sounded upon an uncarpeted stair, a door banged, and all was silent again, save for the ceaseless turmoil far below.

“Sit tight, and catch!” rapped Smith.

Into my extended hands he swung his boots, fastened together by the laces!  Then, ere I could frame any protest, he disengaged his hand from mine, and pressing his body close against the angle of the building, worked his way around to the staircase window, which was invisible from where I crouched.

“Heavens!” muttered Weymouth, close to my ear, “I can never travel that road!”

“Nor I!” was my scarcely audible answer.

In a anguish of fearful anticipation I listened for the cry and the dull thud which should proclaim the fate of my intrepid friend; but no such sounds came to me.  Some thirty seconds passed in this fashion, when a subdued call from above caused me to start and look aloft.

Nayland Smith was peering down from the railing on the roof.

“Mind your head!” he warned—­and over the rail swung the end of a light wooden ladder, lowering it until it rested upon the crest astride of which I sat.

“Up you come!—­then Weymouth!”

Whilst Smith held the top firmly, I climbed up rung by rung, not daring to think of what lay below.

My relief when at last I grasped the railing, climbed over, and found myself upon a wooden platform, was truly inexpressible.

“Come on, Weymouth!” rapped Nayland Smith.  “This ladder has to be lowered back down the trap before another visitor arrives!”

Taking short, staccato breaths at every step, Inspector Weymouth ascended, ungainly, that frail and moving stair.  Arrived beside me, he wiped the perspiration from his face and forehead.