Couldn’t say any of that, so I just said: ‘Genuinely,’ and tried to steer him back to my magnificent discoveries. I was working up to asking him if he thought it was OK to release all trapped creatures – any trapped creature – even if you’d found them in someone’s garden, when he said:

‘You didn’t say what happened with your coat.’

My COAT! My blasted coat … is still in the hedge!

At the exact moment I was thinking this, Sam came to the door with a pair of small binoculars around his neck. ‘We can do an observation from the road,’ he said. ‘But that’s definitely all.’

‘Got to go,’ I told Dad. ‘Bye.’

‘Emergency!’ I yelled at Sam. ‘My stupid puffer coat! Quick!’

Lily appeared on the front lawn and tried to stop us with a tragic speech about Mum not knowing where I was going, and that without permission it was impossible for me to leave, but I laughed in her face.

‘Don’t need it,’ I said, and we started biking. ‘I’ll text her. Gotta go.’

‘I’m in charge while Mum’s at work.’

‘No you’re not. You keep an eye. That doesn’t mean you’re in charge.’

‘Yes it does!’ Lily screamed this at our disappearing backs.

We rode back to Ash House like two mad streaks of lightning, pumping the pedals, not caring how sweaty we got.

‘It’s not here,’ I said, looking at the piece of hedge where my coat should have been. My knees felt very quivery.

The car wasn’t there either. Ash House was deserted again.

Sam stomped around the piece of hedge, still looking, then gave up. ‘So someone’s got it. Tell me it hasn’t got your name in it.’

I nodded. My mouth was dry and horrible.

He shook his head. ‘I told you this whole idea was idiotic. So now there’s solid proof that you were hanging around his house when this thing escaped. Nice one.’

The wind started up in the trees. A minute ago they were waving gently, like friends saying hello. Now they circled round and round, faster and faster.

‘Look at that,’ I said. ‘And it isn’t even windy anywhere else.’

Sam didn’t say anything.

‘Right,’ I said, ‘I’m showing you that box.’

Sam shook his head slowly. ‘No, I’m not getting dragged into this trespassing craziness.’ He made a big show of looking at the waving trees through his binoculars.

I said, ‘You’re too careful.’

‘You’re too sloppy!’

‘I don’t get you, Sam. You’re the science ninja. There’s all this sciency stuff going on in there – inventions and whizzing creatures – and what do you do? You disappear!’