‘I—’ Nora realised she couldn’t say ‘your piano teacher’. And she realised how mad it was, given the fraught context, to say what she was about to say. But still, she said it. ‘Do you have music lessons?’

Leo looked down as the handcuffs were put on him. ‘I ain’t done no music lessons . . .’

His voice had lost its bravado.

The police officer was frustrated now. ‘Please, miss, leave this to us.’

‘He’s a good kid,’ Nora told him. ‘Please don’t be too hard on him.’

‘Well, this good kid just stole two hundred quid’s worth from there. And has also just been found to be in possession of a concealed weapon.’

‘Weapon?’

‘A knife.’

‘No. There must be some mix-up. He’s not that sort of kid.’

‘Hear that,’ the police officer said to his colleague. ‘Lady here thinks our friend Leo Thompson isn’t the kind of kid to get into trouble.’

The other police officer laughed. ‘He’s always in and out of bother, this one.’

‘Now, please,’ the first police officer said, ‘let us do our jobs here . . .’

‘Of course,’ said Nora, ‘of course. Do everything they say, Leo . . .’

He looked at her as if she’d been sent as a practical joke.

A few years ago his mum Doreen had come into String Theory to buy her son a cheap keyboard. She’d been worried about his behaviour at school and he’d expressed an interest in music and so she wanted to get him piano lessons. Nora explained she had an electric piano, and could play, but had no formal teacher training. Doreen had explained she didn’t have much money but they struck a deal, and Nora had enjoyed her Tuesday evenings teaching Leo the difference between major and minor seventh chords and thought he was a great boy, eager to learn.

Doreen had seen Leo was ‘getting caught up in the wrong set’, but when he got into music he started doing well in other things too. And suddenly he wasn’t getting into trouble with teachers any more, and he’d play everything from Chopin through Scott Joplin to Frank Ocean and John Legend and Rex Orange County with the same care and commitment.

Something Mrs Elm had said on an early visit to the Midnight Library came to her.

Every life contains many millions of decisions. Some big, some small. But every time one decision is taken over another, the outcomes differ. An irreversible variation occurs, which in turn leads to further variations . . .

In this timeline right now, the one where she had studied a Master’s at Cambridge, and married Ash and had a baby, she hadn’t been in String Theory on the day four years ago when Doreen and Leo came by. In this timeline, Doreen never found a music teacher who was cheap enough, and so Leo never persisted with music for long enough to realise he had a talent. He never sat there, side-by-side with Nora on a Tuesday evening, pursuing a passion that he extended at home, producing his own tunes.

Nora felt herself weaken. Not just tingles and fuzziness but something stronger, a sense of plunging into nothingness, accompanied by a brief darkening of her vision. A feeling of another Nora right there in the wings, ready to pick up where this one left off. Her brain ready to fill in the gaps and have a perfectly legitimate reason to be on a day trip to Bedford, and to fill in every absence as if she was here the whole time.

Worried she knew what it meant, she turned away from Leo and his friend as they were escorted away to the police car, the eyes of the whole of Bedford high street upon them, and she started to quicken her pace towards the car park.

This is a good life . . . This is a good life . . . This is a good life . . .

A New Way of Seeing

She got closer to the station, passing the garish red-and-yellow zigzags of La Cantina, like a Mexican migraine, with a waiter inside taking chairs off tables. And String Theory too, closed, with a handwritten notice on the door:

Alas, String Theory is no longer able to trade in these premises. Due to an increase in rent we simply couldn’t afford to go on. Thanks to all our loyal customers. Don’t Think Twice, It’s All Right. You Can Go Your Own Way. God Only Knows What We’ll Be Without You.

It was the exact same note she had seen with Dylan. Judging by the date, written in small felt-tip letters from Neil’s hand, it was from nearly three months ago.

She felt sad, because String Theory had meant a lot to people. Yet Nora hadn’t been working at String Theory when it got into trouble.

Well. I suppose I did sell a lot of electric pianos. And some rather nice guitars too.

Growing up, she and Joe had always joked about their hometown, the way teenagers do, and used to say that HMP Bedford was the inner prison and the rest of the town was just the outer prison, and any chance you had to escape you should take it.

But the sun was out now, as she neared the station, and it seemed that she had been looking at the place wrong all these years. As she passed the statue of prison reformer John Howard in St Paul’s Square, with the trees all around and the river just behind, refracting light, she marvelled at it as if she were seeing it for the first time. It’s not what you look at that matters, it’s what you see.

Driving back to Cambridge cocooned in her expensive Audi, smelling almost nauseatingly of vinyl and plastic and other synthetic materials, weaving through busy traffic, the cars sliding by like forgotten lives, she was deeply wishing she had been able to see Mrs Elm, the real one, before she had died. It would have been good to have one last game of chess with her before she passed away. And she thought of poor Leo, sat in a small windowless cell at a Bedford police station, waiting for Doreen to come and collect him.