‘If she is … from the past … why does she wear an old ra-ra skirt and trainers?’ said Kirsty.

Johnny glared angrily at her. She had no right not to care about Paradise Street!

‘Nineteen people got killed! In one night!’ he said. ‘There wasn’t any warning! The only bombs that fell on Blackbury in the whole of the war! The only survivors were two goldfish in a bowl! It got blown into a tree and still had water in it! All the people got killed!’

Kirsty picked up a felt-tipped pen, but it didn’t write because it had dried up. Johnny had a worldclass collection of pens that didn’t work.

She had this infuriating habit of appearing not to notice him when he was excited about something.

‘You know you’ve still got Thomas the Tank Engine on your wallpaper?’ she said

‘What? Have I? Gosh, I hadn’t realized,’ said Johnny, with what he hoped was sarcasm.

‘It’s OK to have Thomas the Tank Engine when you’re seven, and it’s quite cool to have it when you’re nineteen, but it’s not cool at thirteen. Honestly, if I wasn’t here to help from time to time, you just wouldn’t have a clue.’

‘Grandad put it up a couple of years ago,’ said Johnny. ‘This was my room when I stayed with them. You know grandparents. It’s Thomas the Tank Engine until you die.’

Then there was the click of the front door opening.

‘Your grandad?’ hissed Kirsty.

‘He always goes shopping in town on Thursdays!’ whispered Johnny. ‘And Mum’s at work!’

‘Who else has got a key?’

‘Only me!’

Someone started to climb the stairs.

‘But I can’t meet me!’ said Johnny. ‘I’d remember, wouldn’t I? Yo-less says if you meet yourself the whole universe explodes! I’d remember that happening!’

Kirsty picked up the bedside lamp, and glanced at the design on it.

‘Good grief, the Mr Men, you’ve still got Mr—’

‘Shutupshutupshutup. What’re you going to do with it?’

‘Don’t worry, you won’t feel a thing, I learned how to do this in self-defence classes—’

The doorhandle turned. The door opened a fraction.

Downstairs, the phone rang.

The handle clicked back. Footsteps went downstairs again.

Johnny heard the phone picked up. A distant voice said: ‘Oh, hi, Wobbler.’

Kirsty looked at Johnny and raised her eyebrows.

‘Wobbler phoned,’ said Johnny. ‘About going to the movies yest— tomorrow. I just remembered.’

‘Were you on the phone long?’

‘Don’t … think so. And I went to get a sandwich afterwards.’

‘Where’s your phone?’

‘In the front room.’

‘Let’s go, then!’

Kirsty opened the door and darted down the stairs, with Johnny trailing behind her.

His coat was on the coat rack. He was also wearing it. He stood and stared.

‘Come on,’ hissed Kirsty.

She was almost at the bottom when the door started to open.

Johnny opened his mouth to say: oh, yes, I remember, I had to go and get my wallet to see if I’d got any money.