Alleyn, who had seen this pronouncement blowing up for the past five minutes, allowed himself as many seconds in which to be dumbfounded and then asked Marcus if he had any reasons, other, he hastily added, than those already adduced, for making this statement about Harry Grove. Nothing very specific emerged. There were dark and vague allusions to reputation and an ambiguous past. As his temper abated, and it did seem to abate gradually, Knight appeared to lose the fine edge of his argument. He talked of Trevor Vere and said he couldn’t understand why Alleyn dismissed the possibility of his having been caught out by Jobbins, overturned the dolphin and then run so fast down the circle aisle that he couldn’t prevent himself diving over the balustrade. Alleyn once again advanced the logical arguments against this theory.

‘And there’s no possibility of some member of the public having hidden during performance?’

‘Jay assures me not. A thorough routine search is made and the staff on both sides of the curtain confirm this. This is virtually a “new” theatre. There are no stacks of scenery or properties or neglected hiding places.’

‘You are saying,’ said Knight, beginning portentously to nod again, ‘that this thing must have been done by One of Us.’

‘That’s how it looks.’

‘I am faced,’ Knight said, ‘with a frightful dilemma.’ He immediately became a man faced with a frightful dilemma and looked quite haggard. ‘Alleyn: what can one do? Idle for me to pretend I don’t feel as I do about this man. I know him to be a worthless person. I know him – ’

‘One moment. This is still Harry Grove?’

‘Yes.’ (Several nods.) ‘Yes. I am aware that the personal injuries he has inflicted upon me must be thought to prejudice my opinion.’

‘I assure you – ’

‘And I am assuring you – Oh with such deadly certainty – that there is only one among us who is capable of the crime.’

He gazed fixedly into Alleyn’s face. ‘I studied physiognomy,’ he surprisingly said. ‘When I was in New York’ – for a moment he looked hideously put out but instantly recovered, ‘I met a most distinguished authority – Earl P. Van Smidt – and I became seriously interested in the science. I have studied and observed and I have proved my conclusions. Over and again. I have completely satisfied myself – but completely – that when you see a pair of unusually round eyes, rather wide apart, very light blue and without depth – look out. Look out!’ he repeated and flung himself into the chair he had vacated.

‘What for?’ Alleyn inquired.

‘Treachery. Shiftiness. Utter unscrupulousness. Complete lack of ethical values. I quote from Van Smidt.’

‘Dear me.’

‘As for Conducis! But no matter. No matter.’

‘Do you discover the same traits in Mr Conducis?’

‘I – I – am not familiar with Mr Conducis.’

‘You have met him, surely?’

‘Formal meeting. On the opening night.’

‘But never before that?’