only one that was at all clear and distinct was borne in on him.

This was the presence of the lace and the jet beads in the theatre of
the crime. The inference was fair and simple. He came logically and
surely to this:

1. That some woman had entered the compartment.

2. That whether or not she had come in before the crime, she was there
after the window had been opened, which was not done by the murdered
man.

3. That she had leaned out, or partly passed out, of the window at some
time or other, as the scrap of lace testified.

4. Why had she leaned out? To seek some means of exit or escape, of
course.

But escape from whom? from what? The murderer? Then she must know him,
and unless an accomplice (if so, why run from him?), she would give up
her knowledge on compulsion, if not voluntarily, as seemed doubtful,
seeing she (his suspicions were consolidating) had not done so already.

But there might be another even stronger reason to attempt escape at
such imminent risk as leaving an express train at full speed. To escape
from her own act and the consequences it must entail--escape from
horror first, from detection next, and then from arrest and punishment.

All this would imperiously impel even a weak woman to face the worst
peril, to look out, lean out, even try the terrible but impossible feat