hing to gain; perhaps you had
something to save--your professional reputation, for instance. Looking at
it so, it was plain that you were _suppressing_ the cameo--burking it;
since, once taken as you had taken it, it could never come to light again.
That suggested the solution of the mystery at once--you had discovered,
after the sale, that the cameo was not genuine."

"Yes, yes--I see; but you say you began with the knowledge that I broke
into the place myself. How did you know that? I can not imagine a
trace----"

"My dear sir, you left traces everywhere. In the first place, it struck me
as curious, before I came here, that you had sent off that check for five
thousand pounds to Lord Stanway an hour or so after the robbery was
discovered; it looked so much as though you were sure of the cameo never
coming back, and were in a hurry to avert suspicion. Of course I
understood that, so far as I then knew the case, you were the most
unlikely person in the world, and that your eagerness to repay Lord
Stanway might be the most creditable thing possible. But the point was
worth remembering, and I remembered it.

"When I came here, I saw suspicious indications in many directions, but
the conclusive piece of evidence was that old hat hanging below the
trap-door."

"But I never touched it; I assure you, Mr. Hewitt, I never touched the
hat; haven't touched it for months----"

"Of course. If you _had_ touched it, I might never have got the clue. But
we'll deal with the hat presently; that wasn't what struck me at first.
The trap-door first took my attention. Consider, now: Here was a
trap-door, most insecurely hung on _external_ hinges; the burglar had a
screwdriver, for he took off the door-lock below with it. Why, then,
didn't he take this trap off by the hinges, instead of making a noise and
taking longer time and trouble to burst the bolt from its fastenings? And
why, if he were a stranger, was he able to plant his jimmy from the
outside just exactly opposite the interior bolt? There was only one mark
on the frame, and that precisely in the proper place.

"After that I saw the leather case. It had not been thrown away, or some
corner would have shown signs of the fall. It had been put down carefully
where it was found. These things, however, were of small importance
compared with the hat. The hat, as you know, was exceedingly thick with
dust--the accumulation of months. But, on the top side, presented toward
the trap-do