o make arrangements for my joining him in his watch,
and thus again I lost my opportunity of confiding in him regarding
the mysterious girl.

I half anticipated, though I cannot imagine why, that Earl Dexter
would put in an appearance, during the day. He did not do so,
however, for Bristol had put a constable on the door who was well
acquainted with the appearance of The Stetson Man. The inspector,
in the course of his investigations, had come upon what might have
been a clue, but what was at best a confusing one. Close by the
wall of the curator's house and lying on the gravel path he had
found a part of a gold cuff link. It was of American manufacture.

Upon such slender evidence we could not justly assume that it
pointed to the presence of Dexter on the night of the attempted
robbery, but it served to complicate a matter already sufficiently
involved.

In pursuance of Bristol's plan, I concealed myself that evening
just before the closing of the Museum doors, in a recess behind a
heavy piece of Babylonian sculpture. Bristol was similarly
concealed in another part of the room, and Mostyn joined us later.

The Museum was closed; and so far as evidence went the authorities
had relied again upon the bolts and bars hitherto considered
impregnable, and upon the constable in the hall. The broken window
was mended, the cut blind replaced, and within, in its shattered
case, reposed the slipper of the Prophet.

All the blinds being lowered, the Assyrian Room was a place of
gloom, yellowed on the western side by the moonlight through the
blind. The door communicating with the Burton Room was closed
but not fastened.

"They operated last night," Bristol whispered to me, "at the exact
time when the moonlight shone through the hole in the westerly
blind on to the case. If they come to-night, and I am quite
expecting them, they will have to dispense with that assistance;
but they know by experience where to reach the case."

"Despite our precautions," I said, "they will almost certainly
know that a watch is being kept."

"They may or they may not," replied Bristol. "Either way I'm
disposed to think there will be another attempt. Their mysterious
method is so rapid that they can afford to take chances."

This was not my first night vigil since I had become in a sense the
custodian of the relic, but it was quite the most dreary. Amid the
tomb-like objects about us we seemed two puny mortals toying with
stupend