“Okay,” the girl said. She was the elder of the two, perhaps fifteen, and Jem could see streaks of blood on her fingers as she stroked the younger girl’s hair. Dark shadows encircled her eyes, and she looked half-starved, her cheekbones too prominent in her muck-streaked face.

“What’s your name?” Jem asked, still slowly approaching them.

“Ava,” the girl said, sitting up straighter, her confidence growing. Her hair was dyed bright pink beneath the grime, and both ears sported multiple piercings, as if she’d been the class rebel before someone shoved her in a cellar and knocked all the fight from her. “I think Chloe’s broke her ankle. She fell off the crates, and I heard it snap. We were trying to get her phone to work.”

Jem looked at the shattered wooden boxes Ava indicated. Although the girls had managed to improve the phone’s signal, the collapse of the stack explained why no one from ambulance control had been able to contact them again. Jem set her bag at the girls’ feet and unzipped it, ignoring the trickle of cold sweat between her shoulder blades, and trying not to think how easily the call might have been dismissed outright by an overburdened dispatcher, or how many times she had given up after a cursory knock at a probable hoax.

“You did a great job,” she said, forcing brightness into her voice. “Don’t worry, I’ll sort Chloe’s leg for her. Which one is it, Chloe?”

Chloe stared at her for a long moment, her nostrils flaring and her good leg scuffing the floor. Tears had bled mascara down her cheeks, and little remained of her crimson nail varnish. Jem had grown up with girls like Chloe, all attitude and aggression until someone bothered to scratch the surface.

“He said he’d come back for us,” Chloe whispered. “But he never. He just left us in here for days and days.” She started to cry. “I want to go home.”

Rosie knelt beside Jem and put a hand on Chloe’s thigh. Jem could sense the tension radiating off every inch of her, the urge to pepper the girls with questions, to get them to name names and provide descriptions and a full account, but all she did was pass Chloe a tissue.

“Let Jem take a look at your ankle,” she said. “She’s dead gentle, and as soon as she’s done, I’ll give you a piggyback out of here. What do you reckon? Does that sound like a plan?”

Chloe’s head bobbed. She’d cried herself out within seconds. “I’m hungry,” she said.

Jem patted her pockets and pulled a Twix from each. She was happy to take the blame for not keeping Chloe nil by mouth, if it turned out she needed an anaesthetic.