Rosie clung to the armrest and watched rows of grim, grey-washed houses pass by. Thanks to her years on response, she knew the Curzon estate like the back of her hand, knew which of the flats had been colonised by addicts and alcoholics, and where the worst of the recidivists lived. Red door: twenty-eight-year-old male hanging. White door with the scuff marks: domestic assault, vic refused to press charges. North of the precinct, the houses were largely owned by right-to-buy residents, people who had lived on the estate for years, raised their children, scraped together enough for a mortgage, and then watched the area disintegrate around them. Burglaries and car thefts were their main complaints, as they were repeatedly targeted by those on the south side. The crimes reoccurred like clockwork, timed to hit insurance payouts, with the replacement televisions and computers disappearing almost as soon as they entered the houses. The luckier families could afford to move away, but most were stuck fixing bars to their windows and installing alarm systems that everyone ignored.

“Are we, perchance, heading to the south?” she asked.

“Battersby Walk,” Steph confirmed. “Smack bang in the deepest, darkest, southernmost corner.”

“Bleedin’ hell,” Rosie said. “I should’ve stayed in bloody bed.” She and Kash had once spent a particularly lively set of nights on Battersby racking up an assault with a deadly weapon, two heroin overdoses, and a fatal leap from a third-floor balcony, in one record-breaking thirty-six-hour stretch. Even the stray dogs went around there in pairs.

“Aw, come on, no pouting,” Steph said in a tone Rosie recognised all too well. It was the one Steph had used to wrap Rosie round her little finger, to get her to stay out for “just one more drink” or to call in sick when Steph fancied a duvet day. It had lost its efficacy in the end, but now, with Rosie’s guard crumbling beneath three hours’ sleep, it sent a flutter of sensation down her spine that wasn’t altogether unpleasant.

“How many Parker kids are there?” she asked, making a determined return to the business at hand.

“Five now. Girls at eighteen months and eleven, and lads at four, six, and nine. They’ll all be at home, so we should be able to have words with the two eldest, if they’re in any fit state. I’ve written up an interview plan with Social Services, and one of the family liaison officers will be sitting in with us. We’ll probably have to go back tomorrow to finish everything up.”