‘Time,’ he said, ‘is so very misleading. One thinks things take such a long time, but really, of course, they don’t.’

‘No,’ said Miss Marple.

Representing the audience, she moved to a different position. The stage set now consisted of a vast tapestry covered wall going up to dimness, with a grand piano up L. and a window and window seat up R. Very near the window seat was the door into the library. The piano stool was only about eight feet from the door into the square lobby which led to the corridor. Two very convenient exits! The audience, of course, had an excellent view of both of them…

But last night, there had been no audience. Nobody, that is to say, had been facing the stage set that Miss Marple was now facing. The audience, last night, had been sitting with their backs to that particular stage.

How long, Miss Marple wondered, would it have taken to slip out of the room, run along the corridor, shoot Gulbrandsen and come back? Not nearly so long as one would think. Measured in minutes and seconds a very short time indeed…

What had Carrie Louise meant when she had said to her husband: ‘So that’s what you believe — but you’re wrong, Lewis!’

‘I must say that that was a very penetrating remark of the Inspector’s,’ Alex’s voice cut in on her meditations. ‘About a stage set being real. Made of wood and cardboard and stuck together with glue and as real on the unpainted as on the painted side. “The illusion,” he pointed out, “is in the eyes of the audience.” ’

‘Like conjurers,’ Miss Marple murmured vaguely. ‘They do it with mirrors is, I believe, the slang phrase.’

Stephen Restarick came in, slightly out of breath.

‘Hallo, Alex,’ he said. ‘That little rat, Ernie Gregg — I don’t know if you remember him?’

‘The one who played Feste when you did Twelfth Night? Quite a bit of talent there, I thought.’

‘Yes, he’s got talent of a sort. Very good with his hands too. Does a lot of our carpentry. However, that’s neither here nor there. He’s been boasting to Gina that he gets out at night and wanders about the grounds. Says he was wandering round last night and boasts he saw something.’

Alex spun round.

‘Saw what?’

‘Says he’s not going to tell. Actually I’m pretty certain he’s only trying to show off and get into the limelight. He’s an awful liar, but I thought perhaps he ought to be questioned.’

Alex said sharply: ‘I should leave him for a bit. Don’t let him think we’re too interested.’

‘Perhaps — yes, I think you may be right there. This evening, perhaps.’

Stephen went on into the library.

Miss Marple, moving gently round the Hall in her character of mobile audience, collided with Alex Restarick as he stepped back suddenly.

Miss Marple said, ‘I’m so sorry.’

Alex frowned at her, said in an absent sort of way: