‘So, you must have realized that, if she had been going there for a sexual encounter, it was just a quickie?’ I suggested.

‘That was not my immediate thought,’ Walt said rather grumpily.

‘So, did you stop Alexandra then and ask her what she had been doing?’

‘No. I waited to see what she would do next.’

‘And what did she do next?

‘Ally got straight into her car and drove off … drove, I later discovered, straight back to Hastings.’

‘So, did you follow her?’

‘No.’

‘Why not?’

‘I thought I’d watch the building, see who came in and out.’

‘Trying to spot your rival?’

‘Something like that.’

‘And did you see him?’

‘No. I should have trusted Ally. But, as I say, bitter experience. I was possibly a little bit hypersensitive and paranoid.’

I would have said that was something of an understatement. ‘So, when did you leave to go back to Hastings?’ I asked.

‘Round midnight.’

‘And you had it out with Alexandra then?’

‘No. I didn’t go back to her place.’

‘What?’

‘I still have a flat of my own. In St Leonards. I went back there.’

‘Why?’

‘I was still angry with Ally. For keeping secrets from me. I wanted to make her suffer.’

You nasty little tick, I thought. Not for the first time.

‘But then,’ he went on, ‘the next morning, Ally texted me. Told me her mother – the mother I didn’t know she had – had died. Then, obviously, we met up again, and she explained everything.’

‘And now you know about Ingrid’s existence, the fact that she had a mother, why do you think Alexandra didn’t tell you about her earlier?’

‘I think she thought it might affect the purity of our love.’

‘I beg your pardon?’ I said, in a state of wince.

‘Everything was so perfect. Ally and I had found each other. I don’t think she wanted our happiness to be clouded by the presence of the woman who had made her whole life a total misery.’

‘I see.’ I wondered again whether it was more a case of Alexandra not wanting her mother to see what a creep she’d ended up with. But, as I had many times during this conversation, I kept my reactions to myself. My lip was beginning to feel the pain of being constantly bitten.

I did ask, though, why Walt had taken the trouble to call me back.

‘You left a message. Simple politeness,’ he said smugly.

‘Surely there was more to it than that?’

‘Well … Ally texted me to say the police had been in touch with her. She sounded worried. I thought you might know what they’re up to.’

‘Whether they’re suspicious of her, you mean?’

‘Yes.’

‘If they are, you can easily stop that, can’t you?’

‘How do you mean?’

He really wasn’t very bright. I spelled it out for him, ‘The fire that killed Ingrid Richards started – or was started – late on the Tuesday evening or in the early hours of the Wednesday. You witnessed Alexandra leaving Brunswick Square … what time? Before eight, anyway.’