He remained sitting very upright, with his hands on his knees, for some twenty minutes. The car had left London behind and slipped through a frozen landscape. Alleyn, with a deliberate effort, retraced the history of the case: Troy’s long and detailed account, the turgid statements of the Ancreds, the visit to Dr Withers, the scene in the churchyard. What could it have been that Troy knew she had forgotten and believed to be important?

Thomas, with that disconcerting air of switching himself on, broke the long silence.

‘Then I suppose,’ he said very abruptly and in a high voice, ‘that you think either Sonia gave him the children’s medicine or one of us did. But we are not at all murderous people. But I suppose you’ll say that lots of murderers have been otherwise quite nice quiet people, like the Dusseldorf Monster. But what about motive? You say Cedric knew Papa had signed the Will that cut him out of almost everything, so Cedric wouldn’t. On the other hand, Milly didn’t know he’d signed a second Will, and she was quite pleased about the first one, really, so she wouldn’t. And that goes for Dessy too. She wasn’t best pleased, but she wasn’t much surprised or worried. And I hope you don’t think…However,’ Thomas hurried on, ‘we come to Pauline. Pauline might have been very hurt about Paul and Panty and herself, but it was quite true what Papa said. Her husband left her very nicely off and she’s not at all revengeful. It’s not as if Dessy and Milly or I wanted money desperately, and it’s not as if Pauline or Panty or Fenella (I’d forgotten Fenella and Jen) are vindictive slayers. They just aren’t. And Cedric thought he was all right. And honestly,’ Thomas ended, ‘you can’t suspect Barker and the maids.’

‘No,’ said Alleyn, ‘we don’t.’

‘So it seems you must suspect a person who wanted money very badly and was left some in the first Will. And, of course, didn’t much care for Papa. And Cedric, who’s the only one who fits, won’t do.’

He turned, after making this profound understatement, to fix upon Alleyn a most troubled and searching gaze.

‘I think that’s a pretty accurate summing up,’ Alleyn said.

‘Who could it be!’ Thomas mused distractedly and added with a sidelong glance: ‘But, then, you’ve picked up all sorts of information which you haven’t mentioned.’

‘Which I haven’t time to mention,’ Alleyn rejoined. ‘There are Ancreton woods above that hill. We’ll stop at the pub.’

PC Bream was standing outside the pub and stepped forward to open the door of the car. He was scarlet in the face.

‘Well, Bream,’ Alleyn said, ‘carried out your job?’

‘In a manner of speaking, sir,’ said Bream, ‘no. Good afternoon, Mr Thomas.’