Graham's tone was shocked and discouraged.
"What more do you want? Why haven't you arrested him?"
In this room the detective's satisfied chuckle was an offence.
"No good detective would ask that, Mr. Graham. I want my report clean. The coroner will tell us how the old man was killed. I want to tell how young Blackburn got into that room. One of the windows was raised a trifle, but that's no use. I've figured on the outside of the wing until I'm dizzy. There's no way up for a normal man. An orangoutang would make hard work of it. His latch key would have let him into the house, and it would have been simple enough for him to find out that the old man had changed his room. I've got to find out how he got past those doors, locked on the inside."
He chuckled again.
"Almost like a sleep-walker's work."
Bobby shivered. Was that where the evidence pointed? Already the net was too finely woven. The detective continued earnestly:
"I'm figuring on some scheme to make him show me the way. I've a sort of plan for to-night, but it's only a chance."
"What?" Graham asked.
"Oh, no, sir," Howells laughed. "You'll learn about that when the time comes."