“Are you on the premises for the whole of that time?”

Fletcher gave a slight cough. “Well, sir - official - like - if you take my meaning. Sometimes I do stroll out for a breather. I wouldn't be gone more than a couple of minutes or so. Not often, that is.”

“Did you go out last night?”

“No, sir.”

“You're quite sure of that?”

“Yes, sir. It turned that chilly yesterday evening I wouldn't want to, me being what you might call susceptible to cold. I had a bit of a fire in my room downstairs, which the Sergeant here has seen.”

“Small room, I thought,” said the Sergeant. “Draughty, I daresay.”

“It is that,” agreed the porter. “Sit with the door shut?”

“There isn't anything against it, not in my orders,” said Fletcher defensively, “If I'm wanted I'm rung for, and I'd hear the lift working, door or no door. I can keep my eye on things with it shut, on account of the upper part being glass, like you saw.”

“If you weren't having forty winks, you could,” said the Sergeant shrewdly.