‘Sam! What’s happened?’ Her eyes were bright with amazement and she was grinning her head off. I realized it was the first time I’d seen her so excited or interested in anything for ages. She’d been in a bad mood ever since her boyfriend, Stefan Bumgarner, dumped her. (That’s not a joke, by the way. He really is called that.) He’d started going out with another girl who Maeve really hates, Josephine Waxwing. And she’d hardly smiled since. She must have been feeling pretty depressed, I s’pose.

‘How did you get so big?’ she squealed.

‘Growth spurt, I guess.’ I put my hand flat on the pavement in front of her. ‘Climb on, I’ll show you the view from up here!’

They all scrambled up and squashed together on my hand – which to them was about the size of a double bed. I slowly rose up, holding my hand as steady as I could. They were all screaming with laughter and clutching on to each other and sliding about.

It was when they were about ten metres up that the accident happened.

Loren stumbled and caught hold of Lola who also stumbled and they tripped over my thumb – so to save them I tilted my hand – but I tilted it too far and too quickly, and Maeve and Miriam slid off the other side and went plummeting down, screaming their heads off.

I made a desparate grab at them with my free hand, but missed. They hit the pavement with two sickening cracks, like a pair of eggs being dropped.

The crowd gasped.

‘Whoops!’ said Evan.

Maeve and Miriam lay sprawled out, limbs twisted, unmoving.

The helicopters swept down towards the bodies to get better pictures.

A feeling of guilt and dread filled me, as if I’d just smashed two priceless vases in a museum or something, only much, much worse because they weren’t things, they were people, and one of them was my own sister. I’d only had the wishes a few hours and already I’d seriously injured or killed three people. I was like a one-man crime wave.

But I still had the wishes, didn’t I? That was the great thing about having a million wishes (or nine hundred and ninety-nine thousand nine hundred and whatever-it-was). Nothing was unchangeable. Consequences were optional.

‘I wish they were alive again,’ I said. ‘And completely unhurt.’

Maeve and Miriam got up, dusting themselves off. The crowd sighed with relief.

‘Sam, you stupid idiot!’ Maeve shouted up at me.

‘Sorry, bit of a butterfingers there . . .’ That’s one of my mum’s expressions. It seemed to fit.

‘You could have killed us!’

‘Yeah, well, I didn’t.’

I put the other two girls down beside Maeve and Miriam. Carefully.