"Of course I knew that her part in the matter was something like that," he said, "but I'm glad to hear it, just the same." He looked at his friend for a moment and then continued: "But how did you know that Edyth heard a door close immediately after the pistol shot?"
They had just drawn up in front of Hume's, and as Ashton-Kirk got out, he said:
"If you had only used your eyes as we were going over the place," said he, "you'd have no occasion to ask that question."
There was a different policeman at the door; but fortunately he knew the investigator and they were allowed to enter at once. When about half way up the stairs, Ashton-Kirk said:
"This, I think, is about the place where Miss Vale stopped when she saw the light-rays moving across the ceiling and wall of the hall. You get the first glimpse of those from this point. Remain here a moment and I'll try and reproduce what she heard--with the exception of the cry."
Pendleton obediently paused upon the stairs; Ashton-Kirk went on up and disappeared. In a few moments there came a sharp, ringing report, and Pendleton, dashing up the stairs, saw his friend standing holding open the showroom door--the one with Hume's name painted upon it.
"It's the bell," said Ashton-Kirk, pointing to the gong at the top of the door frame. "When I examined it this morning I saw that it was screwed up too tight, and knew that it would make a sound much like a pistol shot to ears not accustomed to it."
Pendleton stared in amazement at the simplicity of the thing.
"I see," said he. "While Edyth stood listening on the stairs someone opened this door!"
"Yes; someone unacquainted with the place. Otherwise he would have known of the bell."
"But how did you know that Edyth heard a door close?"
"Whoever rang the bell closed the door after him. It has a spring lock like the street door; and was locked when Miss Vale tried it a few moments later."
"You say that the ringing of the bell shows the person who rang the bell to have been unacquainted with the place. I think you must be wrong here. Spatola is acquainted with the place; he was here at the time. This is proven by the scream of the frightened cockatoo which followed the ringing of the bell."
"It was not a cockatoo that made the sound," said Ashton-Kirk. "Give me a moment and I think I can convince you of that."