"We'd best put it back on the rug where we found it," said the
sergeant, scratching his puzzled head in his perplexity. "It
will want the best brains in the force to get to the bottom of
this thing. It will be a London job before it is finished." He
raised the hand lamp and walked slowly round the room. "Hullo!"
he cried, excitedly, drawing the window curtain to one side.
"What o'clock were those curtains drawn?"

"When the lamps were lit," said the butler. "It would be shortly
after four."

"Someone had been hiding here, sure enough." He held down the
light, and the marks of muddy boots were very visible in the
corner. "I'm bound to say this bears out your theory, Mr.
Barker. It looks as if the man got into the house after four
when the curtains were drawn, and before six when the bridge was
raised. He slipped into this room, because it was the first that
he saw. There was no other place where he could hide, so he
popped in behind this curtain. That all seems clear enough. It
is likely that his main idea was to burgle the house; but Mr.
Douglas chanced to come upon him, so he murdered him and
escaped."

"That's how I read it," said Barker. "But, I say, aren't we
wasting precious time? Couldn't we start out and scout the
country before the fellow gets away?"

The sergeant considered for a moment.

"There are no trains before six in the morning; so he can't get