But Pinky was not listening to him. She was watching Alleyn.

‘Well, anyway,’ Bertie said crossly. ‘She wouldn’t.’

‘Oh, yes, she would, Mr Saracen,’ Florence said tartly.

‘And did. Quite regular. Standing far enough off to get the fine spray only, which was what she done, as the colonel and Mr Templeton will bear me out, this afternoon.’

‘The point,’ Alleyn said, ‘is well taken, but it doesn’t, I think, affect the argument. Shall we leave it for the time being? I’m following, by the way, a very unorthodox line over this inquiry and I see no reason for not telling you why. Severally, I believe you will all go on withholding information that may be crucial. Together I have hopes that you may find these tactics impracticable.’ And while they still gaped at him he added: ‘I may be wrong about this, of course, but it does seem to me that each of you, with one exception, is most mistakenly concealing something. I say mistakenly because I don’t for a moment believe that there has been any collusion in this business. I believe that one of you, under pressure of an extraordinary emotional upheaval, has acted in a solitary and an extraordinary way. It’s my duty to find out who this person is. So let’s press on, shall we?’ He looked at Charles. ‘There’s a dictionary of poisons in Mr Dakers’s former study. I believe it belongs to you, sir.’

Charles lifted a hand, saw that it trembled, and lowered it again. ‘Yes,’ he said. ‘I bought it a week ago. I wanted to look up plant sprays.’

‘Oh, my goodness me!’ Bertie ejaculated and stared at him. There was a general shocked silence.

‘This specific spray?’ Alleyn asked, pointing to the Slaypest.

‘Yes. It gives the formula. I wanted to look it up.’

‘For God’s sake, Charles,’ Warrender ejaculated, ‘why the devil can’t you make yourself understood?’ Charles said nothing and he waved his hands at Alleyn. ‘He was worried about the damned muck!’ he said. ‘Told Mary. Showed it …’

‘Yes?’ Alleyn said as he came to a halt. ‘Showed it to whom?’

‘To me, blast it! We’d been trying to persuade her not to use the stuff. Gave it to me to read.’

‘Did you read it?’

‘’Course I did. Lot of scientific mumbo-jumbo but it showed how dangerous it was.’

‘What did you do with the book?’

‘Do with it? I dunno. Yes, I do, though. I gave it to Florence. Asked her to get Mary to look at it. Didn’t I, Florence?’

‘I don’t,’ said Florence, ‘remember anything about it, sir. You might have.’

‘Please try to remember,’ Alleyn said. ‘Did you, in fact, show the book to Mrs Templeton?’