A triumphant yell from Rosie cut across his acknowledgement, and Jem ran to find her, following the fresh boot-prints through the undergrowth. She stopped at a tall metal gate that barricaded the side of the house. Rosie was already on the other side, poking her fingers through the thick bars like an inmate in an old-fashioned jail.

Jem leaned forward, winded by the exertion and the stress. “There are two people in the cellar,” she said. “One of them is hurt, and they can’t get out. It’s probably kids who’ve broken in and come a cropper.”

“I should’ve bloody seen this coming,” Rosie said. “We could have been at B&Q slurping up coffee through a Twix, but no…” Her protest lacked any genuine rancour, and she waggled her fingers until Jem touched their tips. “Can you get over? There’s a window round the back we should be able to break and squeeze through. My lot have okayed it, because anyone who might be able to help us is buggering about in the floods.”

“Of course I can get over.” Jem hoisted the bag above her head, standing on tiptoe so Rosie could reach it. “I climbed a fifteen-foot wall on Tuesday.”

“Good point.” Rosie stood clear, giving Jem space to kick off from the top and land on the narrow path. Jem’s boots skidded on the lichen-slickened stone, and Rosie grabbed her arm to stop her from falling.

“Thanks.” Jem clung on for a moment and then stepped cautiously across the most treacherous slab. “Lead the way.”

Rosie had set a wheelie bin and a hefty stone in readiness beneath the window, and she shinned onto the bin as if she’d been born to break and enter. Jem found herself admiring the easy athleticism and the flattering cut of Rosie’s uniform.

“What are you smiling at?” Rosie asked.

Caught red-handed, Jem shrugged. “You,” she said, and Rosie laughed, striking a pose on the lid.

“Is it the Taser? All the girls love the Taser.”

“Amongst other things.” Jem handed her the stone, and Rosie accepted it without question, refocusing on the business at hand. “I’ve got the oxygen cylinder if you prefer a battering ram,” Jem added.

“This’ll do.” Rosie rolled the stone in her gloved palm, assessing its shape, before bashing its sharpest edge against the glass. The outer layer of the double glazing splintered but held, so she tried again, knocking out the pieces as they fell loose. She finished the remainder with her feet, sitting on the bin and booting the stubborn shards into submission. Then she was gone, shimmying through the gap and disappearing into the gloom on the other side. She reappeared just as swiftly. “What a shithole,” she said, lighting the way for Jem.