Callum patted the tree beside him.

This,’ he said, ‘is the tallest tree in Barrow.’

I gazed up the tree. Then I wished I hadn’t. It was twice as tall as the one I fell out of in Skirting. The trunk was thin and wobbly, the topmost branches swaying perilously in the wind that blew down the valley. It was getting stronger and stronger every day now. I was quickly regretting yesterday’s snap decision. Callum strolled towards me.

‘Seeing as you’re so extremely good at tree-climbing,’ said Callum, a grin spreading across his face, ‘you are going to climb it. Right now. The whole thing. Every – last – branch.’

I looked up at the tree again. I’d never tried to climb one like this before. The branches didn’t even look strong enough to hold my weight.

‘Are you … are you sure we have time?’ I said nervously.

Callum nodded. ‘Of course! Curfew doesn’t start for another five minutes! Besides, you organised your cover story – right?’

I had. I’d told my parents that my presentation had got the highest mark in class, before asking if I could stay the next night at Ceri’s as a reward. It was a risky strategy, but it had worked. After promising them that I would wear my knee-pads and sterilise the salad before I ate it, they had relented. After the test was over, I’d stay the night at Callum’s. It was foolproof. Which meant that there was no way I could get out of it now. I could have kicked myself.

‘Off you go then, Fearless Owen,’ said Callum, strolling back to the tree and leaning against it casually. ‘Let’s see how brave you really are!’

I gulped, and made my way to the base of the tree. The remains of a sawn-off stump lay just above my head. I gripped it in one hand, and slowly pulled myself up onto the first branch. I got to my feet, and tried to balanced myself. My legs suddenly wobbled, and I had to grip onto the trunk of the tree.

‘What a great start!’ said Callum, applauding loudly. ‘I certainly hope nothing goes wrong!’

I grit my teeth. I wasn’t going to let myself be humiliated again – not by him. I looked ahead. There was another branch just ahead of me, slightly higher up. In a snap I vaulted over to it, grabbing the trunk again for support as I landed.

‘Hey,’ I heard Callum say from below. ‘Not bad.’

Without a pause I grabbed the next branch above and swung myself onto it, before using the trunk to shimmy up another few feet and elegantly leap onto the branch above that. I glanced down. Callum was staring up, open-mouthed.

‘Whoa,’ he said quietly.

I grinned. ‘I told you I was good.’

I looked around. I could do this. Halfway up to the next branch was a knothole, big enough for my foot. I wrapped my arms around the trunk and wedged my foot inside it. Now, all I had to do was push myself up and reach out to …

‘STOP THAT AT ONCE!’ cried an angry voice from the ground below.

I startled. My legs sprang out like pistons and catapulted me away from the tree like a squirrel, and sent me plummeting to the ground. Fortunately my fall was broken by the patch of stinging nettles at the bottom.

I leapt up, skin on fire. A yellow car was parked in the clearing behind us, the words BARROW TRUANCY OFFICER marked out in big black letters on the side. In front of it stood a man in a bright yellow uniform. He had dark wiry hair, hard eyes, and a mean face. He was staring at me furiously.

Well?’ he barked. ‘What the hell do you two think you’re doing out here?’

I mouthed hopelessly. Answers, explanations, excuses, all evaporated to dust in my mouth. I had no idea what I could possibly say. Callum suddenly leapt forward.

‘Why, Officer Reade!’ he cried. ‘What a surprise! I was just on my way home, actually, and er … got a bit lost …’

‘You live on Magnolia Crescent, Brenner,’ the man growled, swinging round to face him. ‘The other side of the village. Care to explain what you’re doing here two minutes before curfew is due to start?’

Callum slapped his face with shock.

‘Two minutes!’ he gasped. ‘Well, I’d better get going right away, then! Thanks for your help, Officer Reade …’

He made to walk away, but the man threw him a furious glare and Callum stopped in his tracks. The man looked him over as one would a dead rat in a trap, before turning back to me. I squirmed hopelessly in the light of his mean eyes. I couldn’t shake the feeling that he seemed somehow … familiar.

‘Do you know who I am?’ said the man.

I shook my head. The man stepped forwards.

‘I’m Officer Reade,’ he said. ‘The Barrow Truancy Officer. That means that I’m the one who makes sure children in Barrow are either in school or at home.’

I tried to ignore how much my legs were shaking, and the sickening hot-cold floods that were swelling up inside me.

‘And yet,’ he said, throwing a glance at Callum, ‘while I’m patrolling the village on my afternoon rounds, I find two children – two of my own daughter’s classmates! – walking around outside and climbing trees.’ He paused dramatically. ‘Trees! Outside! During an SW5!’

Callum and I squirmed.

‘Do you have any idea how dangerous it is out here?’ Officer Reade cried, the pitch of his voice getting higher and higher. ‘The tornado could land any time! Bears are going to start roaming the valleys soon! Do you want to end up dead? Or in hospital? Or in the County Detention Centre?’ He darted his eyes between us. ‘Well, do you? Because that’s where you two are headed, as far as I’m concerned. Let’s see if you can explain to the Warden himself what you’ve been up to. Ha! I’m sure he’ll be very interested!’

At the mere mention of the name, Callum let out a little squeak. His face had turned pale.

The clock tower in the distance suddenly chimed – once, twice, three, four times.

‘Curfew’s started,’ snapped Officer Reade. He folded his arms. ‘So unless you have a very good reason to be here, then I’m taking the two of you home and explaining to your parents what happened.’

I floundered, my mouth gaping and shutting like a fish on the floor of a boat. That was it. I was done for. My parents were going to kill me.

‘I …’

‘The Dewbridges’!’ Callum suddenly cried, leaping forwards.

Officer Reade looked at him in surprise. I stared at Callum as he flailed his arms wildly.

‘He’s supposed to be staying the night at Ceri Dewbridge’s!’ he said. ‘That’s why we came this way! Owen forgot he was supposed to go to hers tonight, and he didn’t know how to get there, so I said I’d show him myself because he’s new, and we cut through the woods so I could get back in time, but we got lost, and so Owen said he’d climb a tree and find the quickest way out the forest, and …’

‘That true?’ said Officer Reade, turning to me.

I nodded violently. Officer Reade kept his gaze fixed on me for a moment, before turning to Callum.

‘And you?’ he said. ‘Where are your parents?’

Callum paused, and scuffed the ground with his foot.

‘They’re … they’re out of town for the week.’

Officer Reade nodded. ‘Your babysitter at home?’

Callum glowered at him. ‘She’s not my babysi—’

Officer Reade made a growling noise in his throat, and Callum stopped. He looked at the two of us for a while longer, his brain ticking slowly over, his mean eyes flitting between us.

‘That was a very unsafe idea,’ he said eventually. ‘So consider this a warning. Take him to Ceri’s, and then go straight back to yours. Understand?’

Callum nodded quickly. Officer Reade turned back to his car. Then he stopped, and glanced over his shoulder at me.

‘You should probably get out of those nettles,’ he said.

I looked down. Maybe it was the fear, or the adrenaline of plummeting twenty feet to the ground, but I had somehow forgotten that I was standing chest-deep in stinging nettles. I clambered out. Officer Reade stepped back into his car, and quickly sped off through the trees. Callum and I stood in the billowing dust left by the wheels, watching him disappear.

Callum waited until all was silent. Then he picked up a dead branch from the ground and threw it in the general direction of where Officer Reade’s car had headed. It landed with a thump five feet away. Callum turned round in triumph.

‘Ha!’ he bellowed. ‘That showed him!’

I pulled a strand of stinging nettles from out of my helmet with red raw fingers. I couldn’t get Officer Reade’s face out of my head.

‘That man,’ I said. ‘He looked … he looked just like …’

Callum nodded. ‘Yep! He’s Orlaith’s dad. Can you believe it? No wonder she’s such a dork! He’s the one who makes sure nobody leaves their house once curfew starts. He even drives around the village every single night, making sure no one’s on the streets. Honestly, he thinks he’s so hard. Everyone around here’s frightened of him.’

‘But not you,’ I said.

‘Yeah, not me,’ said Callum. ‘Obviously.’ He paused. ‘So, er … yeah. You’re in, I guess.’

I looked back at him. ‘Pardon?’

Callum scratched the back of his head. ‘My gang. The Tornado Chasers. You passed the test. I suppose you’re in now.’

I looked confused. ‘But I wasn’t trying to be in your …’

‘Yeah, well,’ said Callum. ‘You seem to be able to take a lot of injuries without dying, and that could be pretty useful if I ever need a human shield. Might as well let you in, seeing as you’re so desperate for it. It’ll shut you up about it at least.’

‘Er … thanks,’ I said.

Callum held out a hand.

‘Welcome to the gang,’ he said.

I gazed at Callum. For all his faults – and there were lots of them – I had to admit that I’d never met anyone quite like him before. He was big and mean and full of rubbish, but then so are garbage trucks – and they’re pretty hard to ignore when they’re charging full speed ahead. And he had something I couldn’t put my finger on. I’d have never thought up starting up the Tornado Chasers again. It was all Callum’s idea, from the very beginning. Maybe he really was brave. Then again, maybe he was just stupid.

Either way, only an idiot would have agreed to join a plan that was so clearly ridiculous. And unrealistic. And dangerous.

And exciting.

I took his hand.

‘The Tornado Chasers,’ I said.