ough a
door fastened with one of those locks is to break the door down. But
here we have a lock that can be opened with a key. Now the key does not
exist of which one cannot get an impression, and there is not such a
thing as an impression from which one cannot manufacture a false key.
The murderer could easily have got into the house with a duplicate key."

The magistrate raised a further objection.

"If the murderer had got in from outside he would inevitably have left
some traces round about the chateau, but there aren't any."

"Yes there are," Juve retorted. "First of all there is this piece of an
ordnance map which I found yesterday between the chateau and the
embankment." He took it from his pocket as he spoke. "It is an odd
coincidence that this scrap shows the neighbourhood of the chateau of
Beaulieu."

"That doesn't prove anything," said the magistrate. "To find a piece of
a map of our district in our district is the most natural thing
possible. Now if you were to discover the rest of this map in anybody's
possession, then----"

"You may rest assured that I shall try to do so with the least possible
delay," said Juve gently. "But this is not the only argument I have to
support my theory. This morning, when I was walking near the embankment,
I found some very suspicious footprints. It is true there are any number
of footprints near the end of the Verrieres tunnel, where the navvies
are at work. But at the other end of the tunnel, where there is no
occasion for anyone to pass by, I found that the earth of the
embankment, which was crisp with the frost, had been disturbed, showing
that someone had clambered up the embankment; the tips of his shoes had
been driven into the earth, and I could see distinctly where his feet
had been placed; but unfortunately the soil there is so dry that the
footprints were too faint for me to hope to be able to identify the
maker of them. But the fact remains that someone did climb up the
embankment, someone who was making for the railway."

The magistrate did not seem to be impressed by Juve's discovery.

"And pray what conclusion do you think ought to be drawn from that?" he
enquired.

Juve sat down in an easy chair, threw back his head and closed his eyes
as if he were about to indulge in a long soliloquy, and began to express
his thoughts aloud.

"Suppose we were to combine the two hypotheses into one; to wit, that
the murderer was in the chateau prior to the accomplis