“Yours trustfully,

    “J.M.  Jeweler’s Messenger.

    “P.S.—­For heaven’s sake don’t fale, and ask the concerge for
    name of Gestre.”

If it had not been for my rage at not having read this illuminating little document earlier, I should have felt like shouting with joy.  As it was, my delight was tempered with enough of regret to make it easier to restrain myself.

But for the fear that du Laurier might be still with Maxine, I should have rushed back to her house for a moment, just long enough to give her the good news.  But in the circumstances I dared not do it, lest she should curse instead of bless me:  and besides, as there was still a chance of disappointment, it might be better in any case not to raise her hopes until there was no danger of dashing them again.  The best thing was to get the treaty back, without a second of delay.  As for the detective, who was perhaps waiting for me at the hotel, he would have to wait longer, or even go away disgusted—­nothing made much difference now.  Maybe, when once I had the treaty in my hands, I might send a messenger with a few cautious words to Maxine.  No matter how late the hour, she was certain not to be asleep.

The cab I had seen crawling through the street had disappeared long ago, and no other was in sight, so I walked quickly on, hoping to find one presently.  It was now so late, however, that in this quiet part of Paris no carriages of any sort were plying for hire.  Finally I made up my mind that I should have to go all the way on foot; but I knew the direction of the Avenue Morot, though I’d never heard of Rue de la Fille Sauvage, and as it was not more than two miles to walk, I could reach the house I wanted to find in half an hour.

A few minutes more or less ought not to matter much, since “J.  M.” was sure to be awaiting me with impatience; therefore the thing which bothered me most was the effect likely to be produced on the man when I could not hand him over the diamonds in exchange for the treaty.

Of course I didn’t believe that “J.M.” was a jeweller’s messenger, though possibly I might have been less incredulous if Maxine had not told me the true history of the diamonds, and what had happened in Holland.  As it was, I had very little doubt that the rat of a man I had chanced to protect in the railway carriage was no other than the extraordinarily expert thief who had relieved du Laurier of the Duchess’s necklace.

Following out a theory which I worked up as I walked, I thought it probable that the fellow had been helped by confederates whom he had contrived to dodge, evading them and sneaking off to London in the hope of cheating them out of their share of the spoil.  Followed by them, dreading their vengeance, I fancied him flitting from one hiding-place to another, not daring to separate himself from the jewels; at last determining to escape, disguised, from England, where the scent had become too hot; reserving a first-class carriage in the train to Dover, and travelling with a golfer’s kit; struck with panic at the last moment on seeing the very men he fled to avoid, close on his heels, and opening the door of his reserved carriage with a railway key.