The last argument had been the worst, when her dad had taken her home hours late after her last weekend at his flat. Her mum had been sitting on the doorstep of their house, watching for them, and she’d run to the car as Harriet was getting out.

“You bastard, Tony, you selfish little shit,” her mother had shouted – her mother the surgeon, who was always in control, who had never raised her voice before this began. Her curly dark hair bloomed round her head as if energized by her anger; her jeans and jumper hung loosely on her too-thin frame, making her bones look as sharp as her voice. “You’re late, you don’t answer your bloody phone – does it ever occur to you that I might worry? Anything could have happened.”

Harriet stood frozen on the pavement. She’d glimpsed a movement in the open window of the flat next door and knew their neighbor was listening. In the street, a couple walking by with their dog pointedly looked away and increased their pace. She felt her face flush scarlet with embarrassment. “Mum, we only-”

“For God’s sake, Laura,” her father broke in. “We went to the bloody zoo. It was a nice day, and we stayed longer than we meant. Is that a crime?” His voice was level, tight, his face pinched.

“You were supposed to have Harriet back hours ago. You know the rules-”

“Mum, please,” said Harriet, hearing the mortifying quaver in her voice. Her throat ached, and a sharp pain seared her chest. “I’m fine, really. Can we please go in?”

Her father shot her an anguished glance. “Laura, let it go, okay? You’re upsetting Harriet-”

“I’m upsetting Harriet?” Her mother stepped back from the car, looking suddenly, dangerously, calm.

“Listen, it won’t happen again,” Tony said quickly, as if realizing his mistake. “Next time I’ll-”

“There’s not going to be a next time,” her mum had said quietly, taking Harriet’s arm in a viselike grip and turning them both towards the door. As they reached the building, Harriet looked round and saw her dad pulling away, and if he had tried to ring her since, her mum hadn’t told her.

Harriet hadn’t dared ask her mother what she’d meant, but the words had stayed with her over the past few days, disturbing her sleep and haunting her waking hours.

She shifted her backpack and frowned again, aware of a headache coming on. She hadn’t eaten her breakfast and her empty stomach was starting to cramp.

That was one of the worst things about her parents’ separation – now, with her dad gone, when her mother had to work night duty at the hospital, she left Harriet with old Mrs. Bletchley, who lived in one of the cottages across from the school. Mum said Mrs. B. was lonely and enjoyed having children stay with her, but the woman reminded Harriet of the witch in Hansel and Gretel, and her house smelled of cats. That morning she had given Harriet some sort of unspeakable hot cereal for breakfast, which Harriet had mushed around in the bowl and tipped in the bin when Mrs. B. wasn’t looking.

A shiny black Range Rover pulled up to the school gate and a boy climbed from the back, shrugging into his backpack with impossible-to-imitate eleven-year-old cool. Shawn Culver was a year ahead of Harriet, and the most popular boy in school.

“Hey, Harry,” he called out, seeing her watching. She nodded without smiling, determined not to appear impressed, but she didn’t protest his use of the hated nickname. She tugged her hair more tightly into its bunch, suddenly aware that she looked as if she hadn’t bothered to wash that morning – which she hadn’t. And if her hair weren’t bad enough at home, when she could smooth it down with some of her mum’s gel, on a Bletchley morning it was impossible.

The bell rang. She’d turned to follow Shawn with a studied nonchalance when the sound of a car braking fast made her look back. It was a dark green Volvo, like her dad’s – no, it was her dad’s. As she made out his face through the tinted glass, she saw that he was motioning to her. What was he doing here, before school?

She started towards the car slowly, aware of the second ring of the bell, of the play yard emptying behind her. As she neared the car she realized there was a second person in the passenger seat, a woman, and for a moment her heart flared in wild hope.

Then her dad reached back and swung open the rear door, and she saw that the woman was not her mother, but someone she had never seen before.

“Want some coffee, guv?” asked Doug Cullen, popping his head into Detective Superintendent Duncan Kincaid’s office. “I mean real coffee, not that slop,” Cullen added, nodding at the mug on Kincaid’s desk.

Kincaid grimaced at his sergeant and laid down his pen, stretching the stiffness out of his shoulders. “You just want an excuse to get out, and we’ve not been here an hour.” They’d come in early the past few days, catching up on accumulated paperwork, and the warren of cubicles that made up Scotland Yard’s CID had begun to seem more like a prison than an office.

“Guilty.” With his thatch of straight blond hair and wire-framed spectacles, Cullen looked more like a schoolboy than a detective sergeant. But in the year since Kincaid’s former partner, Gemma James, had been promoted to detective inspector and posted to the Metropolitan Police, he had learned to work well with Cullen, respecting the younger officer’s intelligence and dogged persistence when faced with a problem.

Not that Cullen or anyone else could truly replace Gemma as a partner. Although he and Gemma had been living together since the previous Christmas, he found he still missed working with her.

Glancing out his window, he was tempted to play truant along with Cullen, but the pile of paper on his desk argued against it. Besides, the day had gone perceptibly grayer since he’d come in, and he wasn’t in the mood to get drenched. “Okay,” he said, stifling a sigh. “A coffee. But just coffee, mind you, no poncey lattes.”

Cullen grinned and gave him a mock salute. “Right, boss. Back in a tick.”

It was a bad sign, Kincaid thought, when going out on such a dreary morning seemed preferable to work, but administrative reports had never been his strong suit. Not that he didn’t have the aptitude for it; he just lacked the patience. He hadn’t joined the force to become a bloody bureaucrat, yet that seemed more and more the case. And he had reached the point in his career where he felt increasingly pressured to seek promotion, but such a move would mean still less work in the field.

Could he stay where he was, watching the university fast-trackers like Cullen pass him by, without becoming bitter? It was not a prospect he wanted to consider, so with a scowl he turned his attention back to the performance survey on his desk. But when his phone rang a moment later, he leapt on it like a drowning man.

It was his guv’nor’s secretary, summoning him to a meeting with the chief superintendent. Kincaid straightened his tie, grabbed his jacket from the coatrack, and was out the door with only a twinge of regret for his missed coffee.

Chief Superintendent Denis Childs had moved office recently, now commanding a view of the parks and the river, but in spite of his elevated status the man remained as Buddha-like as ever. His round, heavy face betrayed little emotion, but Kincaid had learned to read the slightest flicker in the deep brown eyes half hidden by folds of skin. Today he detected apology, annoyance, and what might have been a trace of worry.

“I’m sorry to put this on you, Duncan,” said Childs, his voice surprisingly soft for a man his size.

Not a promising start, Kincaid thought, settling himself in a chair. Perhaps he should have stayed with the paperwork, after all. “But?”

“But as you have nothing pressing on at the moment, and as you have a knack for soothing ruffled feelings…” – Childs’s lips turned up in the smallest of smiles- “you seemed the best man for the job.”