O n a bleak December morning, the east wind gusting in across the Essex marshes and dousing the city in cold rain, Alison Vlasich decided, finally, to go to the police.

She was standing in her daughter’s room when she reached this decision. The silence inside the flat seemed intensified by the muffled moans and buffeting of the wind outside. It was an uncanny, nagging silence, and in her state, both panicky and weary, she couldn’t decide whether it was really there or whether it was just a numbness inside her head. Then she realised that Kerri’s bedside clock, with its happy Mickey Mouse face and loud comforting tick, was gone.

It had taken two sleepless nights and many hours of fruitless phone calls to bring her to this point. The only time she’d previously rung the police was when old Mr Plum had collapsed outside her front door after he’d returned home to find his flat crawling with preteen burglars. Mrs Vlasich’s 999 call had produced such an intimidating array of sirens and flashing lights that she was inclined not to repeat the experience. No, she thought, on the whole, the best thing would be to go down in person to the local police station and speak to someone face to face about the fear that was now making her feel quite physically sick. This was how they did it on TV on Th e Bill, she told herself, pouring out their troubles to a big, attentive, reassuring desk sergeant with a name like Derek or Stan, who would then take it upon himself to make sure things got properly sorted out.

She put on a little make-up, noticing with surprise how pale she had become, then zipped up her anorak and stepped out onto the rain-swept deck. She hurried away, avoiding the stairs and lifts at this end of the block, following the zigzag route of the deck as it passed through court after court until she came at last to the big ramps at the south-east corner of the estate. Below her she saw the glow of the Tesco shopfront on the other side of the street, the dark bulk of The Merry Jester by the traffic lights, the Esso station opposite, and the concrete framework of the police station, tucked in between the last block of housing and the primary school.