Bristol and I walked slowly in the direction of the entrance of the British Antiquarian Museum. It was the day following upon the sensational scene in my chambers.
 
"There's very little doubt," said Bristol, "that Earl Dexter has the slipper and that Hassan of Aleppo knows where Dexter is in hiding. I don't know which of the two is more elusive. Hassan apparently melted into thin air yesterday; and although The Stetson Man has never within my experience employed disguises, no one has set eyes upon him since the night that he vanished from his lodgings off the Waterloo Road. It's always possible for a man to baffle the police by remaining closely within doors, but during all the time that has elapsed Dexter must have taken a little exercise occasionally, and the missing hand should have betrayed him."
 
"The wonder to me is," I replied, "that he has escaped death at the hands of the Hashishin. He is a supremely daring man, for I should think that he must be carrying the slipper of the Prophet about with him!"
 
"I would rather he did it than I!" commented Bristol. "For sheer audacity commend me to The Stetson Man! His idea no doubt was to use you as intermediary in his negotiations with the Museum authorities, but that plan failing, he has written them direct, thoughtfully omitting his address, of course!"
 
We were, in fact, at that moment bound for the Museum to inspect this latest piece of evidence.
 
"The crowning example of the man's audacity and cleverness," added my companion, "is his having actually approached Hassan of Aleppo with a similar proposition! How did he get in touch with him? All Scotland Yard has failed to find any trace of that weird character!"
 
"Birds of a feather—" I suggested.
 
"But they are not birds of a feather!" cried Bristol. "On your own showing, Hassan of Aleppo is simply waiting his opportunity to balance Dexter's account forever! I always knew Dexter was a clever man; I begin to think he's the most daring genius alive!"
 
We mounted the steps of the Museum. In the hallway Mostyn, the curator, awaited us. Having greeted Bristol and myself he led the way to his private office, and from a pigeon-hole in his desk took out a letter typewritten upon a sheet of quarto paper.
 
Bristol spread it out upon the blotting pad and we bent over it curiously.
 
SIR—
 
I believe I can supply information concerning the whereabouts of the missing slipper of Mohammed. As any inquiry of this nature must be extremely perilous to the inquirer and as the relic is a priceless one, my fee would be 10,000 pounds. The fanatics who seek to restore the slipper to the East must not know of any negotiations, therefore I omit my address, but will communicate further if you care to insert instructions in the agony column of Times.
 
Faithfully,
EARL DEXTER
 
Bristol laughed grimly.
 
"It's a daring game," he said; "a piece of barefaced impudence quite characteristic.
 
"He's posing as a sort of private detective now, and is prepared for a trifling consideration to return the slipper which he stole himself! He must know, though, that we have his severed hand at the Yard to be used in evidence against him."
 
"Is the Burton Room open to the public again?" I asked Mostyn.
 
"It is open, yes," he replied, "and a quite unusual number of visitors come daily to gaze at the empty case which once held the slipper of the Prophet."
 
"Has the case been mended?"
 
"Yes; it is quite intact again; only the exhibit is missing."
 
We ascended the stairs, passed along the Assyrian Room, which seemed to be unusually crowded, and entered the lofty apartment known as the Burton Room. The sunblinds were drawn, and a sort of dim, religious light prevailed therein. A group of visitors stood around an empty case at the farther end of the apartment.
 
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