dies were there, and ordered a
quarter of a ream of paper and envelopes. These were to be sent to an
address in East Grinstead in a hurry. Now, that was very clever and
smart, but here comes the folly. Those people, in the stress of business,
actually forgot to ascertain the cost and pay for the paper, so that it
was down yesterday in my last quarter's bill. Oh, yes, I assure you, the
most brilliant criminals do the most incredibly foolish things."

Ruth looked relieved. Her pretty features relaxed into a smile.

"Then I fancy Reginald Henson has done so," she said. "I fancy I have
solved the mystery of the cigar-case--I mean, the mystery of the one
I bought."

"And which was changed for the one purchased at Walen's, hence these
tears. But Lockharts say that _our_ case was really purchased by an
American."

"Yes, I know. And I fancy that the manager honestly thought so. But I
think I can explain that."

It was David's turn to look up eagerly.

"Do you mean it?" he exclaimed. "It will make a wonderful difference if
you can. That has been one of the most bewildering knots of the whole
puzzle. If we could only trace the numbers of those notes, I suppose
changed at the same time as the cigar-case."

"Indeed they were not," Ruth cried. "I have ascertained that the case was
changed by Henson, as you and I have already decided. Henson made the
exchange not at the time we thought."

"Not when you left the package on the table for him to see?"

"No; at least I can't say. He had the other case then, probably, passed
on to him by Van Sneck. Or perhaps he merely ascertained what I had
purchased. That was sufficient for his purpose. Of course he must have
found out all about our scheme. After I had laid my cigar-case on your
doorstep a man quietly changed it for the other purchased at Walen's. But
this is the alternate theory only. Any way, I am absolutely certain that
you got exactly the same notes that we had placed in the original case."

"That might be," David said, thoughtfully. "But that does not explain the
fact that Lockhart's sold _your_ case to an American at the Metropole."

"I fancy I can even explain that, dear. My uncle came down suddenly
to-day from London. He wanted certain papers in a great hurry. Now, those
papers were locked up in a drawer at 219 given over specially to Mr.
Henson. My uncle promptly broke open the drawer and took out the papers.
Besides those documents the drawer contained a package i