o 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.

All this was merely deduction, for so far as I had seen, "J.M.'s"
travelling companions hadn't even accosted him. Still, the theory
accounted for much that had been puzzling, and made it plausible that a
man should be desperate enough to trust his treasure to a stranger
(known only through "photos in the newspapers") rather than risk losing
it to those he had betrayed.

I resolved to use all my powers of diplomacy to extract from "J.M." the
case containing the treaty before he learned that he was not to receive
the diamonds in its place; and I had no more than vaguely mapped out a
plan of proceeding before I arrived in the Avenue Morot. Thence I soon
found my way into the Rue de la Fille Sauvage, a mean street, to which
the queer name seemed not inappropriate. The h