I thought of his comment, 'A
conundrum?' Why not search for the answer in these white billets, and,
finding it, take the little black bag to the bureau of the 'lost or
found'?

I took up the bag, opened it, hesitated, and put it down. Why should I
read those letters from a stranger, and to a stranger? I leaned out of
the window and drank in the loveliness all about me, illuminated by a
faint young moon.

'A conundrum?' I took up the letter post-marked Boston, and slowly
drew out--ah, it was more than a mere letter that my hand touched that
night. I had put my finger upon a thread in the web of fate!

CHAPTER IV.

'I CAN'T MAKE MYSELF LIKE HIM.'

I am not superstitious, and I certainly had no intimation then of the
part these letters would soon play in my World's Fair adventures, nor
of the use I should make of them; but I opened that letter with an
uncomfortable feeling of curiosity and interest, and without even
pausing to look again at the tiny grotesque faces of that little
bridge procession so artistically sketched upon the envelope.

The letter, like its cover, was dated from Boston, and was just four
days old.

'Just received,' I said to myself, as I took up the wrapper to look at
the Chicago postmark. 'Yes, came last night. She must have read it
this very morning, sitting upon some one of those shaded seats on
Wooded Island, and after reading it she must have amused herself by
copying the people passing over the nearest bridge. Ergo, she must
have been alone.' My detective instincts were rousing themselves;
already I was half unconsciously handling that unread letter as if it
were a 'feature' in a 'case.'

She was alone, too, when we met on Midway; that is, I saw no
companion. Could it be possible that the young lady was really alone
in this densely populated place? How absurd! I looked at the letter
again.

It was written in a beautiful flowing hand, and I said, after a
moment's scrutiny, 'Written in haste and under excitement.' There were
eight closely written pages, and having begun their perusal, I read to
the end without a pause. The letter was signed 'Hilda O'Neil,' and
there was no street number nor post-office box, only the name of the
city from whence it came, Boston.

Hilda O'Neil was the name written on the second letter, this and
nothing more; but this no longer surprised me. Miss O'Neil was a New
York girl, and a guest, at the time of writing, of the sister of her
affianced, i