But his German was so flawless, with no trace of Americanism in voice or accent.  And I knew what good use the German Intelligence had made of neutral passports in the past.  Therefore I determined to go next door and have a look at Dr. Semlin’s luggage.  In the back of my mind was ever that harebrain resolve, half-formed as yet but none the less firmly rooted in my head.

Taking up my candle again, I stole out of the room.  As I stood in the corridor and turned to lock the bedroom door behind me, the mirror at the end of the passage caught the reflection of my candle.

I looked and saw myself in the glass, a white, staring face.

I looked again.  Then I fathomed the riddle that had puzzled me in the dead face of the stranger in my room.

It was not the face of Francis that his features suggested.

It was mine!

* * * * *

The next moment I found myself in No. 33.  I could see no sign of the key of the room; Semlin must have dropped it in his fall, so it behoved me to make haste for fear of any untoward interruption.  I had not yet heard eleven strike on the clock.

The stranger’s hat and overcoat lay on a chair.  The hat was from Scott’s:  there was nothing except a pair of leather gloves in the overcoat pockets.

A bag, in size something between a small kit-bag and a large handbag, stood open on the table.  It contained a few toilet necessaries, a pair of pyjamas, a clean shirt, a pair of slippers, ... nothing of importance and not a scrap of paper of any kind.

I went through everything again, looked in the sponge bag, opened the safety razor case, shook out the shirt, and finally took everything out of the bag and stacked the things on the table.

At the bottom of the bag I made a strange discovery.  The interior of the bag was fitted with that thin yellow canvas-like material with which nearly all cheap bags, like this one was, are lined.  At the bottom of the bag an oblong piece of the lining had apparently been torn clean out.  The leather of the bag showed through the slit.  Yet the lining round the edges of the gap showed no fraying, no trace of rough usage.  On the contrary, the edges were pasted neatly down on the leather.

I lifted the bag and examined it.  As I did so I saw lying on the table beside it an oblong of yellow canvas.  I picked it up and found the under side stained with paste and the brown of the leather.

It was the missing piece of lining and it was stiff with something that crackled inside it.

I slit the piece of canvas up one side with my penknife.  It contained three long fragments of paper, a thick, expensive, highly glazed paper.  Top, bottom and left-hand side of each was trim and glossy:  the fourth side showed a broken edge as though it had been roughly cut with a knife.  The three slips of paper were the halves of three quarto sheets of writing, torn in two, lengthways, from top to bottom.