‘Indeed. Can you tell me, Mr Restarick, who left the Hall yesterday evening whilst you were there — during the relevant time?’

‘Wally — to fix the lights. Juliet Bellever to find a key to fit the study door. Nobody else, as far as I know.’

‘Would you have noticed if somebody did?’

Stephen considered.

‘Probably not. That is, if they just tiptoed out and back again. It was so dark in the Hall — and there was the fight to which we were all listening avidly.’

‘Is there anyone you are sure was there the whole time?’

‘Mrs Serrocold — yes, and Gina. I’d swear to them.’

‘Thank you, Mr Restarick.’

Stephen went towards the door. Then he hesitated and came back.

‘What’s all this,’ he said, ‘about arsenic?’

‘Who mentioned arsenic to you?’

‘My brother.’

‘Ah — yes.’

Stephen said:

‘Has somebody been giving Mrs Serrocold arsenic?’

‘Why should you mention Mrs Serrocold?’

‘I’ve read of the symptoms of arsenical poisoning. Peripheral neuritis, isn’t it? It would square more or less with what she’s been suffering from lately. And then Lewis snatching away her tonic last night. Is that what’s been going on here?’

‘The matter is under investigation,’ said Inspector Curry in his most official manner.

‘Does she know about it herself?’

‘Mr Serrocold was particularly anxious that she should not be — alarmed.’

‘Alarmed isn’t the right word, Inspector. Mrs Serrocold is never alarmed…Is that what lies behind Christian Gulbrandsen’s death? Did he find out she was being poisoned — but how could he find out? Anyway, the whole thing seems most improbable. It doesn’t make sense.’

‘It surprises you very much, does it, Mr Restarick?’

‘Yes, indeed. When Alex spoke to me I could hardly believe it.’

‘Who, in your opinion, would be likely to administer arsenic to Mrs Serrocold?’

For a moment a grin appeared upon Stephen Restarick’s handsome face.

‘Not the usual person. You can wash out the husband. Lewis Serrocold’s got nothing to gain. And also he worships that woman. He can’t bear her to have an ache in her little finger.’

‘Who then? Have you any idea?’

‘Oh yes. I’d say it was a certainty.’

‘Explain, please.’

Stephen shook his head.

‘It’s a certainty psychologically speaking. Not in any other way. No evidence of any kind. And you probably wouldn’t agree.’

Stephen Restarick went out nonchalantly, and Inspector Curry drew cats on the sheet of paper in front of him.

He was thinking three things. A, that Stephen Restarick thought a good deal of himself; B, that Stephen Restarick and his brother presented a united front; and C, that Stephen Restarick was a handsome man where Walter Hudd was a plain one.

He wondered about two other things — what Stephen meant by ‘psychologically speaking’ and whether Stephen could possibly have seen Gina from his seat at the piano. He rather thought not.

III

Into the Gothic gloom of the library, Gina brought an exotic glow. Even Inspector Curry blinked a little at the radiant young woman who sat down, leaned forward over the table and said expectantly, ‘Well?’