“Excellent. No, I won’t arrest you.” Rosie made a rolling gesture. “Carry on.”

Chloe started on a bag of M&Ms, sorting the colours into order on her thigh and making Rosie smile. “Ava taught me how to shoplift,” she said, still arranging the sweets. “Just things we needed, like butties and pop, or things we could sell, like razors. Nance said we were dead good at it.”

“Who’s Nance?”

Chloe nudged an orange M&M into line, her eye contact nonexistent. “She’s just Nance.”

“She came to one of the mills and offered us a job,” Ava said. “There was a lad with her, all decked out in gear. He said she’d given him all kinds of stuff, and we were sick of eating Pot Noodles, so we went with them, and it was fine for the first few days.”

“We got nice clothes,” Chloe said, “and Converse. And Bill showed us a trick to do in the street, where I fell down and pretended like I was unconscious, and Ava pinched purses and phones from everyone who came to help.”

Jem’s monitor suddenly registered a pulse rate of one-twenty. She whacked the alarm to silence it and shook her head, warning Rosie not to intervene. “Ava, did Nance take you to a shelter called Olly’s?” she asked.

Ava stared at her. “How did you know?”

“Bill and Nancy,” Rosie said, the light evidently dawning. “Their surname didn’t happen to be Sykes, by any chance?”

“Dunno,” Ava said. “They were just Bill and Nance.”

“Could you tell us where the shelter is?” Jem asked, her enthusiasm for the new lead making her forget she wasn’t actually a police officer.

Ava filched one of Chloe’s sweets, careful not to disrupt the order. “They took us in one of those big cars, but the windows were black so we couldn’t see much, and Chloe fell asleep.”

“How far from the canal, at a guess?” Rosie asked.

“Half an hour? Maybe. I’m not sure.” Ava chewed her bottom lip with teeth dyed blue by the sweets. “I’m sorry.”

“It’s okay, love. You’re doing really well. The shelter must’ve been great after roughing it at the mill, eh?”

“I suppose,” Ava said. “But we never got to keep any of the cash, and Nance locked us in at night, so we got fed up and tried to do a runner.”

“Who caught you?” Jem asked.

Ava slipped an arm around Chloe’s shoulders. “Bill. He called us ‘ungrateful little twats’ and said we needed to be taught a lesson. Then he locked us in the cellar and left us there.”

Chloe was staring at the wall behind Jem, her expression blank. Tears were running unheeded down her cheeks.

“I think that might be enough for now,” the social worker said.