"Humph! that's what I thought; but what proof have you?"
Villiers put his hand in his pocket and brought out a large knife.
"I found this just under the window," he said, handing it to Naball. "You'll see there's blood on the handle, so I'm sure it was with it the crime was committed."
"But how do you know it's Stewart's knife?" asked Naball.
Villiers placed his finger on one side of the handle.
"Read that," he said briefly.
"From Meg," read Naball.
"Exactly," said Villiers. "Meg is Kitty Marchurst's child, and she gave it to Keith Stewart."
"By Jove, it looks suspicious," said Naball. "He is in possession of a large sum of money, and can't tell how he got it. He can't account for his time on the night of the murder, and this knife with his name on it is found close to the window through which the murderer entered--humph!--things look black against him."
"I suppose you'll arrest him at once?" said Villiers malignantly.