She moved to the door. Stephen opened it for her, and as she stepped into the hall, she gave an uncontrollable start, for Joseph was there.
"Ah, there you are, Tilda!" Joseph said. "I was just coming to look for you! Tea-time, my dear! Hallo, Stephen, old boy! Now, what mischief have you two been hatching, I should like to know?"
"Mathilda's got a bit of a head; she's going to lie down," Stephen said, closing the door behind him. "Did you say tea was ready?"
"Oh, poor Tilda!" Joseph exclaimed, concerned. "Can I get you anything for it, my dear? Would you like an aspirin? I'm sure Maud has some."
"I shall be all right if I lie down," Mathilda replied. "It's nothing much: I often get these heads."
"Come on, Joe, leave her alone!" said Stephen, opening the door into the drawing-room. "Tea!"
"With you in one moment, old man!" Joseph said. "I'm just going to wash my hands."
Mathilda had gone upstairs. Stephen heard her cross the hall above, and go into her room. He watched Joseph follow trippingly in her wake, smiled grimly, and went into the drawing-room.
The Inspector, emerging from the library, found the coast clear, and went at once to the first half-landing. Dropping on his knees there, he closely scrutinised the stair-carpet. It was a thick, grey pile, and here and there a few small stains were visible on it. The Inspector discovered two brown spots on the half-landing, and, having looked at them through his magnifying-glass, produced a safety-razor blade from a small case in his pocket, and carefully cut these away from the carpet. He placed the severed tufts of pile in a container, and rose from his knees. "I'm going back to the station," he said briefly. "You stay here and keep your eye on our clever customer. It's just on the cards he may have been listening outside the library door. Tail him!"
The Sergeant, who had been thinking deeply, said: "Chief, if it's true - why did he stab him in the back? That wasn't how that chap killed the Empress, according to what you read out!"