the vicinity of the Court of Honour and the
Administration Building. It's the Princess Eulalia's day, you
remember; or had you failed to note that?'

'Go on, boy; wound me where I'm weakest,' scoffed Dave.

But I chose to ignore Dave's chaff.

'I suggest that we join the crowd early, and stay with it late.'

'Done!' cried he.

'It's hard to tell where they will elect to work. There will be a
thinning out inside the buildings, but a crowd outside, and such a
crowd as this will be--all with necks craned and attention fixed;
ladies in gay attire, the cream of the city's visitors as well as the
other side; and there will be at least half a dozen false cries of
"There she comes!" and somebody's pocket will suffer at each cry.'

'Right you are!' agreed Dave. 'It'll be a swell crowd, and it's my
opinion that our men will be in the thick of it.'

* * * * *

Early the next morning I went to see if anything had been reported
concerning the diamond robbery, for as yet little had been
accomplished. There was one of the attendants, a young woman, whom I
had felt uncertain about. She was pretty, and I thought artful and
vain; and I had learned from another employe of the Lausch Pavilion
that she had formed the acquaintance of a rather flashily dressed
person wearing much jewellery, and that just before the robbery she
had been seen to receive two or three slyly-delivered _billets-doux_.
The girl was being closely watched, and one of the guards, who was
stationed near, and who was said to have been seen loitering near the
pavilion oftener and longer than was needful, was likewise under close
surveillance.

But this morning there was something to report. It did not come
through any of the men at work upon the case, nor was it in the nature
of a discovery. It was an anonymous letter, and it came through the
United States mail, having been posted in Chicago, at the up-town
post-office.

It was addressed 'To whom it may concern,' at the bureau, and was
brief and to the point.

'If you do not want to waste time,' the letter began, 'turn your
attention to the men in charge of the robbed jewellery exhibit; and if
you also keep an eye upon a certain up-town man who keeps a place
advertised as a "jewellery-store," and with rather a shady
reputation--a man not above doing a little business in uncut gems,
say, in a very quiet way--you may find some of the lost gems between
the two.'

There was no s