A bruised figure was walking quickly towards us. He looked all around to see who else might observe him here, before sitting. ‘What do you want?’ he said in an angry tone. ‘I’m busy.’ I gazed at Grest’s face, curious to know how he had explained to his colleagues the marks that Tibbot’s fists had left on him.

‘Doing such important work,’ I replied.

‘Tell me what you want or I leave.’

I didn’t think he would, but there seemed little point in pushing him. ‘You said before that on the day she died, you heard me go into the bathroom, and then she shouted, “Who’s there? I can’t see.” ’

‘So?’

‘Why would that be? That she couldn’t see?’

He took a long look at me. ‘You’re a proper one, aren’t you?’

‘Mrs Cawson has a new friend,’ said Tibbot. ‘Comrade Fellowman. He’s best mates with Guy Burgess, you know.’

‘A true guardian angel.’

‘So you really should answer the question. Was there something wrong with her sight?’

Grest waited again before answering. He was beginning to enjoy himself. ‘Tart was blind as a fucking bat. At least she was then.’

So that confirmed what I thought. ‘Did you do that to her?’ Tibbot demanded. ‘Smack her too hard?’

‘No.’

‘Stop lying to us!’

‘I’m not, mate. She was like that when I got there.’

Tibbot looked at him suspiciously. ‘Slipped your mind to tell us last time, did it?’

Grest leaned back casually, watching the truth dawn on us. ‘Don’t work for you, do I? I wasn’t exactly in the mood to natter.’

‘But you are now?’

He smirked. ‘Well, I’ve been thinking about it. You see, Cawson called me the day before it happened. Said she was doing the dirty on us and I had to go round there to get the last of the stuff and the ledger. Now when I got there, I found her pegging out and myself in the middle of it all. So I had no choice – I had to keep the blues away from it and make sure no one investigated too far. You want to tell me the timing was coincidence?’

I understood what he was implying. ‘But how could Nick plan it like that?’ I said, confused.

‘He’s the doctor, not me. Something in her food, her drink. That Champagne, I should think. It wouldn’t need to be to the minute.’

No, it wouldn’t have to be to the minute. Just so long as Grest was there around the same time, he would make sure any investigation was superficial. But then I had stumbled in and set everything awry. Poor us. Poor Lorelei.

‘What did he use?’

‘Don’t ask me. Ask him.’

‘What exactly did he say?’ Tibbot asked, tapping his fingers together thoughtfully at the information.