There was a longish pause. Grantley lifted his head. Somewhere beyond the screens a trolley jingled down the ward.

‘Ping.’

‘That must have rocked them,’ Alleyn said.

‘Can say that again. What a turn-up! Oh, dear!’

‘How did you do it? Just like that? With your mouth?’

The house-surgeon stirred restively. The sister gave a starched little cough.

‘Do you mind?’ Trevor said. ‘My mum plays the old steely,’ he added, and then, with a puzzled look: ‘Hey! Was that when I got knocked out or something? Was it?’

‘That was a bit later. You had a fall. Can you remember where you went after you banged the stage-door?’

‘No,’ he said impatiently. He sighed and shut his eyes. ‘Do me a favour and pack it up, will you?’ he said and went to sleep again.

‘I’m afraid that’s it,’ said the house-surgeon.

Alleyn said: ‘May I have a word with you?’

‘Oh, certainly. Yes, of course. Carry on, Sister, will you? He’s quite all right.’

Alleyn said: ‘Stick it out, Grantley.’

The house-surgeon led him into an office at the entrance to the ward. He was a young man and, although he observed a markedly professional attitude, was clearly intrigued by the situation.

‘Look here,’ Alleyn said, ‘I want you to give me your cold-blooded, considered opinion. You tell me the boy is unlikely to remember what happened just before he went overboard. I gather he may recall events up to within a few minutes of the fall?’

‘He may, yes. The length of the “lost” period can vary.’

‘Did you think he was on the edge of remembering a little further just now?’

‘One can’t say. One got the impression that he hadn’t the energy to try and remember.’

‘Do you think that if he were faced with the person whom he saw attacking the caretaker, he would recognize him and remember what he saw?’

‘I don’t know. I’m not a specialist in amnesia or the after effects of cranial injury. You should ask someone who is.’ The doctor hesitated and then said slowly: ‘You mean would the shock of seeing the assailant stimulate the boy’s memory?’

‘Not of the assault upon himself but of the earlier assault upon Jobbins which may be on the fringe of his recollection: which may lie just this side of the blackout.’

‘I can’t give you an answer to that one.’

‘Will you move the boy into a separate room – say tomorrow – and allow him to see three – perhaps four visitors: one after another? For five minutes each.’

‘No. I’m sorry. Not yet.’

‘Look,’ Alleyn said, ‘can it really do any harm? Really?’

‘I have not the authority.’

‘Who has?’

The house-surgeon breathed an Olympian name.

‘Is he in the hospital? Now?’

The house-surgeon looked at his watch. ‘There’s been a board meeting. He may be in his room.’

‘I’ll beard him there. Where is it?’

‘Yes, but look here – ’