‘But he was hit by a car.’

‘There is a difference, Nora, between dying in a road and being hit by a car. In your root life Voltaire lived longer than almost any other life, except the one you’ve just encountered, where he died only three hours ago. Although he had a tough few early years, the year you had him was the best of his life. Voltaire has had much worse lives, believe me.’

‘You didn’t even know his name a moment ago. Now you know he had restrictive cardio-whatever?’

‘I knew his name. And it wasn’t a moment ago. It was the same moment, check your watch.’

‘Why did you lie?’

‘I wasn’t lying. I asked you what your cat’s name was. I never said I didn’t know what your cat’s name was. Do you understand the difference? I just wanted you to say his name, so that you would feel something.’

Nora was hot with agitation now. ‘That’s even worse! You sent me into that life knowing Volts would be dead. And Volts was dead. So, nothing changed.’

Mrs Elm’s eyes twinkled again. ‘Except you.’

‘What do you mean?’

‘Well, you don’t see yourself as a bad cat owner any more. You looked after him as well as he could have been looked after. He loved you as much as you loved him, and maybe he didn’t want you to see him die. You see, cats know. They understand when their time is up. He went outside because he was going to die, and he knew it.’

Nora tried to take this in. Now she thought about it, there hadn’t been any external signs of damage on her cat’s body. She had just jumped to the same conclusion that Ash had jumped to. That a dead cat on the road was probably dead because of the road. And if a surgeon could think that, a mere layperson would think that too. Two plus two equals car accident.

‘Poor Volts,’ Nora muttered, mournfully.

Mrs Elm smiled, like a teacher who saw a lesson being understood.

‘He loved you, Nora. You looked after him as well as anyone could. Go and look at the last page of The Book of Regrets.’

Nora could see that the book was lying on the floor. She knelt on the floor beside it.

‘I don’t want to open it again.’

‘Don’t worry. It will be safer this time. Just stick to the last page.’

Once she had flicked to the last page, she saw one of her very last regrets – ‘I was bad at looking after Voltaire’ – slowly disappear from the page. The letters fading like retreating strangers in a fog.

Nora closed the book before she could feel anything bad happen.

‘So, you see? Sometimes regrets aren’t based on fact at all. Sometimes regrets are just . . .’ She searched for the appropriate term and found it. ‘A load of bullshit.’

Nora tried to think back to her schooldays, to remember if Mrs Elm had said the word ‘bullshit’ before, and she was pretty sure she hadn’t.

‘But I still don’t get why you let me go into that life if you knew Volts was going to be dead anyway? You could have told me. You could have just told me I wasn’t a bad cat owner. Why didn’t you?’

‘Because, Nora, sometimes the only way to learn is to live.’

‘Sounds hard.’

‘Take a seat,’ Mrs Elm told her. ‘A proper seat. It’s not right, you kneeling on the floor.’ And Nora turned to see a chair behind her that she hadn’t noticed before. An antique chair – mahogany and buttoned leather, Edwardian maybe – with a brass bookstand attached to one arm. ‘Give yourself a moment.’

Nora sat down.

She stared at her watch. No matter how much of a moment she gave herself it stayed being midnight.

‘I still don’t like this. One life of sadness was enough. What is the point of risking more?’

‘Fine.’ Mrs Elm shrugged.

‘What?’

‘Let’s do nothing then. You can just stay here in the library with all those lives waiting on the shelves and not choose one.’

Nora sensed Mrs Elm was playing some kind of a game. But she went along with it.

‘Fine.’

So Nora just stood there while Mrs Elm picked up her book again.

It seemed unfair to Nora that Mrs Elm could read the lives without falling into them.

Time went by.

Although technically, of course, it didn’t.

Nora could have stayed there for ever without getting hungry or thirsty or tired. But she could, it seemed, get bored.

As time stood still, Nora’s curiosity about the lives around her slowly grew. It turned out to be near impossible to stand in a library and not want to pull things from the shelves.

‘Why can’t you just give me a life you know is a good one?’ she said suddenly.

‘That is not how this library works.’

Nora had another question.

‘Surely in most lives I will be asleep now, won’t I?’

‘In many, yes.’

‘So, what happens then?’

‘You sleep. And then you wake up in that life. It’s nothing to worry about. But if you are nervous, you could try a life where it’s another time.’

‘What do you mean?’

‘Well, it’s not night-time everywhere, is it?’

‘What?’

‘There are an infinite number of possible universes in which you live. Are you really saying they all exist on Greenwich Mean Time?’