clever thieves often
enough."

But there was a very dogged, resolute expression on his plain face,
nevertheless, as he turned it northward, which betrayed that he did not
mean to give up his search quite yet.

That afternoon when Mona went down to dinner, the clerk of the hotel
waylaid her and quietly slipped an envelope into her hand.

"Thank you," she said, in a low tone, and hastily concealed it in her
pocket.

When she was alone again she broke it open and read, with almost as much
disappointment as the detective himself had experienced, when he found
that his birds had flown, these words:

"Gone! They gave us the slip about eleven o'clock. Save the scrap of
cloth--it may be needed later. R."

"Oh, dear!" sighed Mona, regretfully; "and the Palmer robbery is still as
much of a mystery as ever."

CHAPTER X.

THE PLOT AGAINST MONA THICKENS.

The next morning Mrs. Montague and her young companion left the Southern
Hotel and proceeded directly on board one of the palatial steamers which
ply between St. Louis and New Orleans.

Mrs. Montague secured one of the best staterooms for their use, and
immediately made herself comfortable for the trip.

The weather was very fine, the season advanced, for the foliage was
rapidly developing to perfection, and the sail down the broad tortuous
river was delightful.

Mona enjoyed it, in spite of her dread of meeting Louis Hamblin at the
end of it, and her anxiety to get back to New York and Ray.

Mrs. Montague had entirely recovered her good nature; indeed, she had
never been so kind and gracious toward her seamstress as during this
portion of their trip. She appeared to exert herself to make her enjoy
it--was more free and companionable, and an observer would have regarded
them as relatives and equals.

Mrs. Montague made many acquaintances, as she always did everywhere, and
entered most heartily into every plan for amusing and entertaining the
party on board the steamer.

The days were mostly spent in delightful intercourse and promenades on
deck, where Mona was put forward and made to join in the pleasures; while
the evenings were devoted to tableaux, charades, music, and dancing, as
the passengers desired.

It seemed almost like a return to her old life before her uncle's death,
and could she have obliterated all sadness and painful memories, Mona
would have enjoyed it thoroughly.

They had barely touched the levee at New Orleans when they espied Loui