At 3.23 a.m. the hospital call to say a heart’s been found. Put like that, it almost sounds funny, as if someone’s just discovered it in a rubbish bin or on a doorstep like happens in the news sometimes with tiny babies.

Except that’s not how it is.

What they really mean is someone’s died. A stranger, carrying a donor card, has stopped living. It’s hard not to think of that person’s family and what the hospital have had to tell them tonight. Yet without that donor heart my little brother will stop living too.

So for once, I think we’re the lucky ones.

The first I know of it is a beeping noise near my head. It’s my brother Theo’s favourite and most annoying joke. Last time he set my alarm clock for 3 a.m. I got him back by putting cheese in his pillowcase. But nowadays it’s mostly me who’s washing the bed linen and buying the cheese, so I’m a bit more sensible.

The beeping goes on. It’s not my clock. And as my brain catches up, I remember I can’t blame Theo either. These past few weeks he’s slept in the dining room because he can’t climb the stairs any more. Once we’d moved his bed in and put up his Doctor Who posters it looked like a normal kid’s bedroom, if you ignored the oxygen tank and the plastic box full of pills.

The beeping is coming from the room next door. It sounds like Mum’s pager, the one given to her for emergencies. My stomach goes into knots.

There’s a thud. An ‘Ouch!’ The beeping stops.

I hear Mum’s door open. That creaky third step tells me she’s going downstairs. The kitchen light clicks on and she starts talking fast. I lie very still to listen.

‘We’ll be there, doctor,’ says Mum.

Two years ago Theo blew out his birthday cake candles in one big puff then collapsed right in front of us on the carpet. We thought he was mucking about at first, but then his lips went blue like they do when you’ve been swimming in the sea too long.

When the ambulance came Mum tried to be cheerful; she even offered the paramedics some of Theo’s cake. Then came the hospital tests – X-rays, scans, needles that left bruises on the back of Theo’s hands; it got harder to stay cheerful after that. A virus had attacked my brother’s heart, so the doctors said, which apparently can happen to anyone. Except Theo isn’t ‘anyone’: this stupid, random thing has happened to us.

There’s a different sort of beeping now as Mum sends a text. Then she’s waking Theo. I can’t hear her actual words but her voice is high-pitched like she’s telling him we’re going somewhere exciting. Next she’s back upstairs, opening my door.

‘Alice?’ Mum hisses. ‘You awake?’

I am. Wide awake. Like she’s chucked water in my face.

‘What’s happening?’ I say.

‘A heart’s become available.’

My stomach knots get tighter. I wriggle up the bed and turn on the bedside lamp.

‘And is it …?’

Mum leans against the doorframe. Her hair is all on end. She’s smiling and crying at the same time.

‘Yes,’ she says, ‘it’s a perfect match.’

*

Twenty minutes later we’re in the car. The hospital is in London, which is 110 miles south down the motorway. We’ll need to get a move on because a donor heart doesn’t last long. They pack it in ice and inject it with potassium to stop it beating. After that, it’s only good for four to six hours.

Theo sits in the back, oxygen line in his nose. He’s managed to sneak his dinosaur toys in with him; there are T-rexes and diplodocuses and triceratopses all over the seat.

‘You’ll have to give those to Mum when we get there, buddy,’ I say, as I fasten my seatbelt.

‘Will I, Mum?’ Theo sounds worried.

Mum looks in the driver’s mirror. ‘Don’t worry, love. I’ve heard nurses are BIG dinosaur fans.’

Then she glares at me.

‘What?’ I say. ‘It said “no toys” in that booklet from the hospital because of germs.’

‘I know that,’ says Mum, but I’m guessing she’d rather not think about it. There are so many things that could go wrong, and the leaflet lists quite a few. ‘Can’t we think of something nice like … I don’t know … chocolate cake or Christmas or …’

‘… unicorns and fairies …’ I slouch down in my seat. ‘All right, I get it.’

We take the main road through town, passing shops, then pubs, then takeaways. Mum’s driving faster than normal.

‘Aren’t you dropping me at Lexie’s?’ I say, as we don’t take the turning to my best friend’s house. Ever since we knew Theo needed a transplant, this has been the plan. The hospital has space for Mum to stay, but not me.

‘Sorry love.’ She pats my knee. ‘I texted her mum but she can’t have you tonight. She thinks the baby’s on its way. Great timing, huh?’

I stare out of the window. Bite down on my lip. No tears. Not now.

‘You’re disappointed, aren’t you?’ Mum says.

I shrug. Staying at Lexie’s is a treat these days. It happens so rarely, what with Mum working and Theo being ill. But now the baby’s coming and Lexie’ll be so excited that I can’t feel bad about it. And Kate, her poor mum, looks ready to burst.

‘So am I coming to the hospital?’ I ask.

‘Just ’til we sort something out.’

I don’t much like the sound of this. I mean, it’s not like I can stay with Dad or anything. Not unless she fancies sending me all the way to Devon.

‘I’d be fine at home on my own, you know. I can look after myself,’ I tell her.

‘I don’t doubt it for a minute, sweetie,’ Mum says. ‘But you’re under sixteen so the law advises that you shouldn’t be left alone overnight.’

A sinking feeling hits my stomach. This isn’t the sort of thing my mother normally knows. Or says.