Louise, with a curious expression, as if connecting his two passengers.
Then he went on through the train, but the girl's heart was beating high
and the little man, while seeming to eye the fleeting landscape through
the window, wriggled somewhat uneasily in his seat,

Mary Louise now decided he was a detective. She suspected that he had
been sent to Beverly, after the other man left, to watch her movements,
with the idea that sooner or later she would rejoin her grandfather.
Perhaps, had any letter come for her from her mother or Gran'pa Jim,
this officer would have seized it and obtained from it the address of
the man he was seeking. That would account for their failure to write
her; perhaps they were aware of the plot and therefore dared not send
her a letter.

And now she began wondering what she should do when she got to Dorfield,
if the little man also left the train at that station. Such an act on
his part would prove that her suspicions were correct, in which case she
would lead him straight to her grandfather, whom she would thus deliver
into the power of his merciless enemies.

No; that would not do, at all. If the man followed her from the train at
Dorfield she dared not go to Peter Conant's house. Where, then, COULD
she go? Had she possessed sufficient money it might be best to ride past
Dorfield and pay her fare to another station; but her funds were
practically exhausted. Dorfield was a much bigger town than Beverly; it
was quite a large city, indeed; perhaps she could escape the supervision
of the detective, in some way, and by outwitting him find herself free
to seek the Conant's home. She would try this and circumstances must
decide her plan of action. Always there was the chance that she
misjudged the little man.