Stephen braced himself and went down. The man in the hall was an obvious detective⁠—square built and solid, with hard grey eyes and a dark walrus moustache, a bowler hat in his hand. In the other he held the end of a yellow sack, muddy in patches and discoloured.

“Sorry to trouble you, sir, but can you tell me anything about this sack? I’m a police officer,” he added unnecessarily.

Stephen felt extraordinarily cool.

He said, “Can’t say, Inspector. Sacks are very much alike. We had one in the scullery once, but⁠—” He had the sack in his hands now, looking for the label.

“And what happened to your sack, sir?” said the man smoothly.