“Africa, I think. It were on ITV,” the second girl said. “But they got one in Chester Zoo, Woody, I seen it.”

Rosie’s ears pricked up at the mention of the lad’s name. She walked across to them, her presence completely ignored until she stopped a couple of feet away from their smouldering disposable barbecue and cleared her throat. The trio were slouching on the floor in a nest of blankets and sleeping bags. The girl with her back to Rosie craned her neck, grinning as she viewed Rosie upside down. Her lank hair—blond, streaked through with bright green—fell about her face, and her tongue piercing flashed gold in the torchlight.

“Hiya. You’re dead pretty. D’ya want a burger?” She rolled over clumsily, scrabbling about on the floor to retrieve a dirt-speckled barmcake housing a disc of grey meat.

“Uh, no. Cheers, though,” Rosie said. With none of the kids showing any inclination to do a runner, she sat on a spare crate at Woody’s side.

Woody sucked on his joint and then seemed to realise he’d made a grave mistake, not in smoking a Class B substance in front of a police officer, but in not offering her a toke. “It’s really good shit,” he said, turning the spliff’s soggy side toward her.

“It’s tempting, but I’ll pass, thanks.”

He shrugged at her refusal and unscrewed a half-empty bottle of cider. “Have you ever been to Chester Zoo?” he asked, regarding her with red-rimmed eyes and scratching at a scab on his cheek.

Rosie crossed her legs at the ankles, settling in for the long run. “Yeah, once, I think. Why?”

“Did you see the unicorn?”

The blond girl laughed so hard that her alcopop shot out of her nose.

“Ah,” Rosie said as their earlier exchange began to make sense. “I don’t believe it was there at the time, so no.”

“I’ve never been to a zoo,” he said. “I shot a squirrel with an airgun once, but it’s not the same as seeing a real-life unicorn.”

Rosie nodded, doing her utmost to remain professional. “Maybe you should do a bit of googling when you get home.”

The second girl—ghostly pale and Goth to the nth degree, with self-harm scars running the length of both forearms—held out a tube of Smarties and tipped a few into Rosie’s palm. “We’ll tell him later,” she whispered.

Rosie colour-ordered her Smarties on her knee and started with a purple one. “Break it gently,” she said. “It’ll be like finding out about Father Christmas all over again.”

The Goth girl giggled. “He still spends half of Christmas Eve hanging out of the window with a pair of binoculars he won on a tombola.” Her brow suddenly furrowed as she noticed Rosie’s uniform for the first time. “Shit. Are you going to arrest us for the weed?”