They said good night and left the theatre in ones and twos. Gaston wore his black cloak clutched histrionically above his chest in an actor’s hand. He bowed to Alleyn and said: ‘Good night, sir.’

‘Good night, Mr Sears. I’m afraid the fight was a severe ordeal: you are still breathless. You shouldn’t have been so enthusiastic.’

‘No, no! A touch of asthma. It is nothing.’ He waved his hand and made an exit.

The stagehands went at once and all together. At last there was only Nina Gaythorne and one man left, a pale, faintly ginger, badly dressed man with a beautiful voice.

‘Good night, Superintendent,’ he said.

‘Good night, Mr Barrabell,’ Alleyn returned and became immersed in his notebook.

‘A very interesting treatment, if I may say so.’

‘Thank you.’

‘If I may say so, there was no need, really, to revive anything before Macbeth’s exit and from then up to the appearance of his head. About four minutes, during which time he was decapitated.’

‘Quite so.’

‘So I wondered.’

‘Did you?’

‘Poor dotty old Gaston,’ said the beautiful voice, ‘having to labour through that fight. Why?’

Alleyn said to Fox: ‘Just make sure the rooms are all locked, will you, Mr Fox?’

‘Certainly, sir,’ said Fox: He walked past Barrabell as if he was not there, and disappeared.

‘One of the old type,’ said Barrabell. ‘We don’t see many of them nowadays, do we?’

Alleyn looked up from his notebook. ‘I’m very busy,’ he said.

‘Of course. Young Macduff is not with us, I see.’

‘No, Mr Barrabell. They sent him home. Good night to you.’

‘You know who he is, of course?’

‘Of course.’

‘Oh? Oh well, good night,’ said Barrabell. He walked away with his head up and a painful smile on his face. Nina went with him.

‘Br’er Fox,’ said Alleyn when that officer returned, ‘let us consider. Is it possible for the murder to have been performed after the fight?’

‘Just possible. Only just. But it was.’

‘Shall we try? I’ll be the murderer. You be Macbeth. Run into the corner. Scream and drop down. Hold on.’ He went into the dark area, OP. ‘We’ll imagine the Macduff. He runs after you and goes straight on and away. Ready? I’m using my stopwatch. Three, two, one, zero. Go.’

Mr Fox was surprisingly agile. He imitated swordplay, backed offstage, yelled and fell at Alleyn’s feet. Alleyn had removed the imaginary dummy head from the imaginary claidheamh-mor. He raised the latter above his shoulder. It swept down. Alleyn let go, stooped and seized the imaginary head. He fixed it on the point of the claymore and rammed it home. He propped it in its corner, dragged the body (Mr Fox weighing fourteen stone) into the darkest corner, and clapped the dummy head down by it. And looked at his watch.