Robin locked the phone and dropped it onto the passenger seat. She fired up the engine, feeling guilty. When Maggie had suggested working solo, she’d jumped at it because it gave her an opportunity. Thursday was one of the two days Ana had picked Peter up from school, Kath had told her, so if normally she would have been with him, maybe she’d be at home now. Catching her might be a challenge otherwise: she seemed to work round the clock, cleaning and cooking somewhere ’til mid-afternoon, babysitting in the evenings, too, quite often, after she’d finished with them. She had a son of her own back in Slovakia who was in a tennis academy; she’d come to the UK to pay for it.

Kath hadn’t had Ana’s number but she’d had her address in her SatNav: she’d dropped her home from babysitting one night when they’d been out, the four of them, and she’d been the designated driver. They’d got back after midnight, and she hadn’t felt comfortable putting Ana on a bus or on her own in an Uber. Robin remembered Gamil, Maggie’s friend at the bakery. He’d seen Becca get out of an Uber or a private cab, hadn’t he, some time just before dawn in October. She’d looked wobbly – he’d thought she was drunk. Had she been using then? She made a mental note to add it to the board.

From Ladywood, her own SatNav brought her out through Selly Park and Stirchley to a cul-de-sac off Allens Croft Road. She parked round the corner and walked.

At first glance, the close looked pretty decent. It was separated from the main road by a bushy hedge on both sides and several tall trees, another complete row of which formed a backdrop for the houses at the far end. In the summer, it was probably very green. The houses themselves looked decent, too, steep-roofed semi-detached Fifties builds in red brick, patches of front garden shaped and sized according to their position round the tarmac bulb. As Robin got closer, though, the initial impression began to tarnish. One of the houses had been awkwardly converted into flats, two identical front doors jammed side by side and, behind the wall, the garden next door was just a square of cracked concrete knotted with dog shit. A caravan parked further along had had its wandering days.

Ana’s house was at the end of the bulb, furthest from the main road. It was mid-afternoon now, just after three o’clock, but the curtains in the ground-floor bay were drawn. Weeds covered the lawn, and a plastic trough of rain-flattened earth by the step was full of groundsel.