'I'll drink to that!' said Emma, gazing forlornly at the locked drinks cabinet.

'You're very brave,' said Mrs Beatty, who was sitting next to me. She patted my hand in a kindly manner. 'What was his name?'

'Landen. Landen Parke-Laine. He was murdered by the ChronoGuard in 1947. I'm going to the Goliath Apologarium tomorrow to try to get his eradication reversed.'

There was a murmuring.

'What's the matter?'

'You must understand,' said a tall and painfully thin man who up until now had remained silent, 'that for you to progress in this group you must begin to accept that this is a problem of the memory – there is no Landen; you just think there is.'

'It's very dry in here, isn't it?' muttered Emma unsubtly, still staring at the drinks cabinet.

'I was like you once,' said Mrs Beatty, who had stopped patting my hand and returned to her knitting. 'I had a wonderful life with Edgar and then, one morning, I wake up in a different house with Gerald lying next to me. He didn't believe me when I explained the problem, and I was on medication for ten years until I came here. It is only now, in the company of your good selves, that I am coming to the realisation that it is only a malady of the head.'

I was horrified.

'Mother?'

'It's something that we must try and face, my dear.'

'But Dad visits you, doesn't he?'

'Well, I believe he does,' she said, thinking hard, 'but of course when he's gone it's only a memory. There isn't any real proof that he ever existed.'

'What about me? And Joffy? Or even Anton? How were we born without Dad?'

She shrugged at the impossibility of the paradox.

'Perhaps it was, after all, youthful indiscretions that I have expunged from my mind.'

'And Emma? And Herr Bismarck? How do you explain them being here?'

'Well,' said my mother, thinking hard, 'I'm sure there's a rational explanation for it . . . somewhere.'

'Is this what this group teaches you?' I replied angrily. 'To deny the memories of your loved ones?'

I looked around at the gathering whose members had, it seemed, given up in the face of the hopeless paradox that they lived every minute of their lives. I opened my mouth to try to describe eloquently just how I knew Landen had once been married to me when I realised I was wasting my time. There was nothing, but nothing, to suggest it was anything other than in my mind. I sighed. To be truthful, it was in my mind. It hadn't happened. I just had memories of how it might have turned out. The tall thin man, the realist, was beginning to convince everyone they were not victims of a timeslip, but delusional.

'You want proof—'