‘Yes, and perhaps you bloody well are,’ Pollock burst out. ‘Sitting there, like Jacky. How do we know—’

‘You don’t,’ Caley said. ‘So shut up.’ He turned to Alleyn. ‘But about this—about Miss Hewson. Why, to begin with, are you so sure there’s been foul play?’

Alleyn said: ‘We are waiting for an official medical opinion. In the meantime, since we have a doctor among us, I think I shall ask him to describe the post-mortem appearances of suffocation by earth and gravel. As opposed to those following an attack from behind involving abrupt and violent pressure on the carotid arteries.’

‘Ah no!’ Caley cried out. ‘Alleyn, I mean—surely!’ He looked at Hewson who leant on the table, his face in his hands. ‘I mean,’ Caley repeated. ‘I mean—well—there are decencies.’

‘As far as possible,’ Alleyn rejoined, ‘we try to observe them. Mr Hewson will be asked to identify. He may prefer to know, if he doesn’t know already, what to expect.’

‘Know!’ Hewson sobbed behind his fingers. ‘Know. My God, how should I know!’

‘You all want to know, I gather, why we believe Miss Hewson was murdered. Our opinion rests to a considerable extent on post-mortem appearances. Dr Natouche?’

It was a long time since they had heard that voice. He had been there, sitting apart in his splendid gown and scarlet slippers. They had shot uneasy, resentful or curious glances at him but nobody had spoken to him and he had not uttered.

He said: ‘You have sent for your police consultant. It would be improper for me to give an opinion.’

‘Even in the interest of justice?’

‘It is not clear to me how justice would be served by my intervention.’

‘If you consider for a moment, it may become clear.’

‘I think not, Superintendent.’

‘Will you at least tell us if you would expect to find a difference between post-mortem appearances in these two cases?’

A long silence before Dr Natouche said: ‘Possibly.’

‘In the case of an attack on the carotids you would expect to find external post-mortem marks on the areas attacked?’

‘Superintendent, I have told you I prefer not to give an opinion. The external appearances from suffocation vary enormously. I have—’ He waited for some seconds and then spoke very strongly. ‘I have never seen a case of death from a murderous assault on the carotids. My opinion would be valueless,’ said Dr Natouche.

Pollock cried out shrilly: ‘You’d know how to do it, though, wouldn’t you? Wouldn’t you?’

Hewson lowered his hands and stared at Natouche.

‘Any medical man,’ Natouche said, ‘would know technically, what death by such means involved. I must decline to discuss it.’