My grandparents only live a couple of streets away and I can cut through the park to get to their place. In fact, if they hadn’t built the new houses at the bottom of our road I’d have been able to see their house from my bedroom window.

The reason they live quite so close is because when I was younger I had this hole in my heart. Which sounds pretty weird, I know. I mean, what does that even look like? I always imagined being able to stare through it like my heart was a doughnut. But it wasn’t actually like that. I mean, for one thing there wasn’t pink icing and sparkly hundreds and thousands lining my insides like on a doughnut, which would at least have made up for stuff a bit. But I was pretty poorly when I was little and so Nana and Grandad moved here to help look after me while Mum and Dad were at work.

When I was about five I had to have an operation because the doughnut hole wasn’t closing up like they’d hoped. When I heard the word ‘operation’ I thought it would be like that game where you have to fish things out with tweezers. And I couldn’t stop worrying that I’d make this horrible buzzing noise and startle the doctor so much he’d fling my heart across the room. But he reassured me that he’d played that game for years and never been buzzed, not once, so I let him do the operation, for real. And he did a good job.

But Mum and Dad still won’t accept that it’s mended now and I’m better. They still think I’m fragile and would like to put me in one of those giant plastic balls you can bounce around in at fairs, to keep me safe. It’s a good job Grandad’s here; he’s a firm believer in ‘letting kids be kids’.

He says I need to be allowed to find stuff out for myself. Even if sometimes that means I get a few bumps and scrapes.

Like the time I showed him my design for roller skates after Mum and Dad refused to get me some. It involved a lot of Blu-Tack, Sellotape and biros. But he let me build them anyway. It wasn’t a total success, but I did learn how much the floor hurts when you hit it with your face. Which is in itself an important lesson, so Grandad said.

So, like I say, I’m totally fine now. Apart from being a teeny bit on the teeny side – and the doctor said I’ll probably shoot up like a bean one day. But I’m still waiting for that.

On the upside, it means Nana and Grandad live only two minutes and forty-five seconds away. On the downside, I can’t help wondering if all that looking after me was what made Grandad poorly. Because now he has a funny heart, and not the funny-ha-ha kind. Mum and Dad insist it’s nothing to do with me, and Nana says it’s more likely because of all the trifle and cheese he used to eat, but I still can’t help thinking Grandad was supposed to be retired and taking it easy, not running round after me. I wasn’t a patient patient. I didn’t like being poorly, and sometimes when I watched my friends all playing footie and I wasn’t allowed I used to get really cross. I even remember shouting at Grandad and hiding from him on purpose – so he had to hunt for me for ages. Which can’t have been very nice – or restful.

But whenever I start to worry about him he accuses me of sticking him in a giant plastic ball. So even though there’ll always be this little raw bit deep down in my belly whenever I think of that, I keep it to myself.

When I arrived that morning I headed straight round the back. I could see Nana through the kitchen window, leaning over a huge saucepan, steam swirling up around her. A sweet, fruity smell came floating out towards me.

I gave her a wave and hurried down the garden, across the neat lawn, through the little group of apple and pear trees with their low crooked branches and on past the abandoned beehives, which Grandad is always promising to clean up but never has.

And then I saw him in the far corner, spade poised, ready to tear up the roots of the dragon-fruit tree. I shrieked and ran towards him.

‘Grandad. Stop!’

‘Hey-up, Chipstick. Hope you’ve brought your muscles,’ he said. ‘We need to shift this thing. Then we can start planning what’s going where.’

He pointed his spade at the dangly cactus-like tentacles.

‘But, Grandad,’ I panted, trying to catch my breath, ‘I found out what it is. It’s a dragon-fruit tree.’ I quickly stepped in front of his outstretched spade. ‘I looked it up last night.’

Grandad’s face wrinkled. ‘Never heard of one of those.’

He angled the spade again, ready to do battle.

‘I thought I could look after it,’ I spluttered.

‘But it’s taking up half the veggie plot. We could get some nice beans in there. Wouldn’t you prefer some nice beans?’

I shook my head till I thought my brains would fall out, then blurted out the only thing I could think of that might make him change his mind. ‘Didn’t you want some fancy fruit? Think of it: dragon-fruit jam. You don’t get many dragon-fruit jam tarts, do you?’

Grandad rested on his spade and peered across at me. He was giving me his ‘What are you up to?’ look. Then he winked and said, ‘Best tell Nana to prepare for some dragon-fruit crumble as well then, hey?’

He turned away and began battling with a bramble. I breathed a sigh of relief. Pulling open my pocket, I stared down at the little dragon curled inside. His bright diamond eyes twinkled back up at me.