‘You stop, now,’ the man shouted. ‘I’ll crack your heads.’

Oli was solid, but he wasn’t in the best shape. ‘Wait up,’ he gasped, clutching his side as Leon streaked ahead.

While Leon reached a main road and sprinted past Costa Coffee, Oli found the paint-spattered man and his excited dog closing to within a few metres. Realising that he couldn’t outrun his opponent, Oli scrambled through a gate and ripped a windmill ornament out of a neat front garden. It was made of plastic, but weighted with a concrete base.

The big man overshot the gate, then a combination of leaves underfoot and the enthusiastic Rottweiler tugging on its leash sent him skidding into a painful set of splits. Oli was delighted for two seconds, between his pursuer’s agonised yell and the moment when he let go of the dog’s leash.

‘No!’ Oli yelled.

The twelve-year-old lobbed the windmill, but it just glanced the eighty-kilo dog in the side. After thinking about doubling back towards the gate, Oli made a run at the hedge leading into the next garden. He got a good jump, and would have scrambled over if the Rottweiler hadn’t got a paw on his tracksuit bottoms, dragging him down on to the manicured lawn as a woman stuck her head out of the front door fifteen metres away.

‘Help me!’ Oli screamed, getting sprayed with saliva as the dog jumped on his chest, ripping off barks.

He had no way of knowing that this was one of the CHERUB campus guard dogs, trained to bark and contain rather than maul. As the dog’s writhing weight smeared Oli into the damp grass, he caught a glance of the paint-strewn man struggling to his feet, only to get kicked – fake-kicked – dramatically down by a boy who’d sprinted in from across the road.

Oli realised it was Daniel as the woman by the door ran inside to call the cops. After vaulting the gate, Daniel closed up behind the barking dog and snatched its leash. It took all his strength to haul it back, just long enough for Oli to roll free. As the dog turned to pounce on Daniel, the fourteen-year-old stumbled back and hooked the end of the leash over a fence post.

‘Move your butt,’ Daniel ordered, hitching Oli up by his trackies and throwing him over the hedge, before grabbing the laptop out of the churned-up lawn and making the dive himself.

Oli was confused by the chain of events, but his pursuer appeared to be unconscious and Leon had doubled back and was waiting on the pavement as they exited through another front gate.

‘How slow are you?’ Leon jibed, as Daniel gave Oli a shove in the back.

Muddy, shocked and with strings of dog spit in his face, Oli felt Daniel grab his neck and shove him forward. ‘The cops are gonna be here, start running.’