"All tight," said he. "A Caspar window holder."
The door leading to the hall was fitted with a large old-fashioned lock, from which protruded a copper key.
"That looks safe enough," said Fuller, as he glanced at this.
"If it were fast it might be," said the other, drily. "But I had occasion to use it while you had the lights out, and found it unlocked."
Nanon was summoned and Ashton-Kirk met her in the hall.
"This door," said he; "is it usually left unlocked?"
"Never," she answered. "Dr. Morse always had it fast from the inside. He kept his books and papers there, and did not care to have them disturbed."
"That will do," said Ashton-Kirk. The old woman was just about to turn away when there came a loud peal at the door-bell.
"The police," said Fuller.
"Go and see," said Ashton-Kirk to Nanon.