n one of
Lockhart's big linen-lined envelopes--a registered letter envelope, in
fact. My uncle had little time to spare, as he was bound to be back in
London to-night. He suggested that as the back of the drawer was broken
and the envelope presumably contained valuables, I had better take care
of it. Well, I must admit at once that I steamed the envelope open. I
shouldn't have done so if Lockhart's name had not been on the flap. In a
little case inside I found a diamond bracelet, which I have in my pocket,
together with a receipted bill for seventy odd pounds made out to me."

"To you?" David cried. "Do you mean to say that--"

"Indeed I do. The receipt was made out to me, and with it was a little
polite note to the effect that Messrs. Lockhart had made the exchange of
the cigar-case for the diamond bracelet, and that they hoped Miss Gates
would find the matter perfectly satisfactory."

David was too astonished to say anything for the moment. The skein
was too tangled to be thought out all at once. Presently he began to
see his way.

"Under ordinary circumstances the change seems impossible," he said.
"Especially seeing that the juggling could not have been done without
both the cases--but I had forgotten how easily the cases were changed. I
have it! What is the date of that letter?"

Ruth slowly unfolded a document she had taken from her purse.

"The day following what you call your great adventure," she said. "Henson
or somebody took the real case--my case--back to Lockhart's and changed
it in my name. I had previously been admiring this selfsame bracelet, and
they had tried to sell it to me. My dear boy, don't you see this is all
part of the plot to plunge you deeper and deeper into trouble, to force
us all to speak to save you? There are at least fifteen assistants at
Lockhart's. Of course the ultimate sale of the cigar-case to this
American could be proved, seeing that the case had got back into stock
again, and at the same time the incident of the change quite forgotten.
And when you go and ask questions at Lockhart's--as you were pretty sure
to do, as Henson knew--you are told of the sale only to the American.
Depend upon it, that American was Henson himself or somebody in his pay.
David, that man is too cunning, _too_ complex. And some of these days it
is going to prove his fall."

David nodded thoughtfully. And yet, without something very clever and
intricate in the way of a scheme, Henson could not have