r open behind him."

"It seems to me more likely that he escaped by the window, even if he
did not enter that way. Miss Heredith, who was the last inmate of the
household to see Mrs. Heredith alive, thinks that the window was closed
when she was in the room before dinner."

Merrington walked over to the window and examined it, testing the lock
and looking at the sill.

"Does Miss Heredith say that the window was locked, or merely closed,
when she was in the room?" he asked.

"She cannot say definitely. She thinks it was closed because the air was
heavy, and she knew that Mrs. Heredith disliked having her bedroom
window open."

Merrington shrugged his shoulders contemptuously.

"A woman's fancies are not much to build a theory upon," he said. "Have
you any other reason for thinking that the murderer may have escaped by
this window?"

"Yes. After the shot was fired the guests rushed upstairs immediately,
and the murderer would have run into them if he had attempted to escape
downstairs."

"Is there no other means of escape from the wing except by the
staircase?"

"There is the back staircase I told you of, at the end of the corridor.
That staircase is never used. The door is kept locked, and the key hangs
in a room downstairs. It was the door at the bottom of this staircase
which was found unlocked by the butler yesterday evening."

"I'll have a look at it, and then we'll go downstairs. I want to see
this bedroom window from outside."

They left the bedroom and proceeded to the end of the corridor, where
Caldew pointed out the door at the top of the staircase. Merrington
opened it, and went down the stairs. He reappeared after the lapse of a
few minutes with dusty hands and cobwebs on his clothes.

"The murderer didn't get in that way," he said. "On the face of it, it
seems a plausible theory to suggest that he entered by the locked door
and hid himself somewhere in this wing, and escaped after committing the
murder by jumping through the bedroom window. But it is impossible to
get over your point that if he had entered by the door he would have
tried to escape by the same means, not knowing that the door had been
locked in the meantime. To do that he must have traversed the corridor
twice and gone down and up these back stairs while the guests were
coming up the other stairs. He couldn't have done it in the time. He
would have been caught--cut off before he could get back. Look at this
steep flight of sta