oment.
Muller never seemed to need sleep or food when he was on the trail,
particularly not in the fascinating first stages of the case when it
was his imagination alone, catching at trifles unnoticed by others,
combining them in masterly fashion to an ordered whole, that first led
the seekers to the truth. Now he went over once more all the little
apparently trivial incidents that had caused him first to watch the
Thorne household and then had drawn his attention, and his suspicion, to
Adele Bernauer. It was the broken willow twig that had first drawn his
attention to the old garden next the Thorne property. This twig, this
garden, and perhaps some one who could reach his home again, unseen and
unendangered through this garden--might not this have something to do
with the murder?

The breaking of the twig was already explained. It was Johann Knoll
who had stepped on it. But he had not climbed the wall at all, had
only crept along it looking for a night's shelter. And there was no
connection between Knoll and the people who lived in the Thorne house.
Muller had not the slightest doubt that the tramp had told the entire
truth that day and the day preceding.

Then the detective's mind went back to the happenings of Tuesday
morning. The little twig had first drawn his attention to the Thorne
estate and the people who lived there. He had seen the departure of
the young couple and had passed the house again that afternoon and the
following day, drawn to it as if by a magnet. He had not been able
then to explain what it was that attracted him; there had been nothing
definite in his mind as he strolled past the old mansion. But his
repeated appearance had been noticed by some one--by one person
only--the housekeeper. Why should she have noticed it? Had she any
reason for believing that she might be watched? People with an uneasy
conscience are very apt to connect even perfectly natural trivial
circumstances with their own doings. Adele Bernauer had evidently
connected Muller's repeated passing with something that concerned
herself even before the detective had thought of her at all.

Muller had not noticed her until he had seen her peculiar conduct that
very morning. When he heard Franz's words and saw how disturbed the
woman was, he asked himself: "Why did this woman want to be shown the
spot of the murder? Didn't she know that place, living so near it, as
well as any of the many who stood there staring in morbid curiosity