Finally, the headlights died and the Shogun rolled the last few yards in darkness. After it stopped, there was silence for a moment, then the whirr of a window lowering, the creak of seat leather as a body shifted position, and the slow, careful scrape of metal. With a final click and a grunt, the movement stopped. From a position near the driver’s seat came a green glow and a faint electronic beeping.

A hundred yards away, in Rose Shepherd’s house, the clock was softly chiming three as the bedside phone began to ring.

2

Monday, 24 October

Detective Sergeant Diane Fry pushed at the half-open door and stepped carefully past the tape. In the hallway, she had to squeeze past a child’s bike propped against the wall, one wheel off and a spanner on the saddle. She almost tripped over two bulging bin liners full of clothes, ready to go to the charity shop, or maybe the launderette. The smell in the house was overpowering, despite a cold draught blowing through the rooms from the broken windows.

‘Home, sweet home,’ said a voice behind her.

DC Gavin Murfin leaned on the front door, forcing it back against the bin liners with an ominous creak of hinges and a popping of plastic.

‘I hope you remembered to wipe your feet, Diane,’ he said. ‘We wouldn’t want to ruin the décor.’

Fry felt her shoulders stiffen inside her jacket. From the moment she’d entered the house, the fabric of her clothes had begun to feel prickly and uncomfortable, as if the sensitivity of her skin was suddenly heightened, her nerve endings screaming in sympathy with the dead.

‘Shut up for a bit, Gavin, will you?’

Murfin sniffed, and rattled the empty sweet wrappers in his pocket. Fry did her best to ignore him. Everyone dealt with these things in their own way, of course. Gavin’s instinct was to retreat behind a flippant façade. For Fry, the urge was to focus on small details, the trivialities that could so easily be missed if you saw only the big picture.

The first thing she needed to know was how much evidence had been preserved from the original scene, and what had been interfered with. Here, in this house in Darwin Street, she could see at a glance there had been far too much interference. For a start, someone had disturbed the opened post that lay on the hall table, where it lay in a pool of dirty water. She poked at the envelopes with a finger. One of them seemed to be a packet of photographs back from the printers, and another was a BT phone bill. On the bottom were a couple of polling cards for next month’s county council by-election. Some local politician had just lost a voter.

Surrounded by the remains of a family’s day-to-day existence, Fry paused for a moment, listening to the slow drip of water from a ceiling, the crack of a splintered window frame. Her eyes drifted across the muddy carpet to the walls, scratched and gouged by passing equipment – hose reels, breathing apparatus, stretchers. Her attention settled on the incongruous chrome gleam of the spanner, still waiting for someone to pick it up and replace the wheel of the bike.

‘Ugh. The Marie Celeste, with extra charcoal.’

Fry lacked the energy to answer Gavin this time, let alone to shut him up. It was too early in the morning, and she was too depressed at having been on call when something like this came in. Derbyshire’s E Division didn’t catch an incident like this more than once every ten years or so. Of course, Edendale had house fires like anywhere else, but it was bad luck when someone died in one. Today was unlucky all round.

At least the structure of the building was intact. From the street, it had been hard to tell that anything serious had happened, except for the broken windows and the scorch marks where flames had licked the walls. It might just have been a rowdy party that had got out of hand. Inside, it was a different story. Whether the story was anything to do with her, Fry had yet to find out.

Fry tried to tune down her senses as she followed the approach path towards the tape that marked the inner cordon. She realized that the hallway smelled a bit like her kitchen – charred bacon and evaporated steam. When it was her turn to kick the bucket, this was the way she imagined it would be. She’d be a kitchen accident statistic, one more victim of a faulty toaster, killed by an exploding microwave. Death in the throes of breakfast.

At the foot of the stairs, she turned right into the sitting room, keeping carefully to the stepping plates. Judging by what the neighbours reported, the occupants of 32 Darwin Street had been taken by surprise. Six weeks ago, Lindsay Mullen had ordered a new carpet for her lounge. It had a deep, thick pile, and it was a shade of cream Lindsay had always wanted, but her husband insisted wasn’t practical. It would show up the dirt, he’d said. It was a shameful waste of money.

Royal Wilton in chamomile, that was it. According to the uniforms who’d taken initial statements, the lady in the house to the left had heard the entire argument as Brian Mullen left for work one morning.

Fry looked around the wrecked lounge. Mr Mullen had been right. The carpet was black now, and trampled with charred debris. Dozens of boot prints had sunk into two inches of filthy sludge.

The problem was, the bottom edge of the door into the kitchen had sealed so tightly against the new Wilton that there was no gap for air to get through. When the sofa ignited, thick smoke would have filled this room in minutes, choking fumes that seared the lungs and stung the eyes. If only a few wisps of it had seeped under the door into the kitchen, they might have reached the smoke alarm, and the outcome could have been different. Unlike so many others, the Mullens’ alarm had been working, the batteries recently replaced. It just hadn’t detected any smoke until it was too late. Far too late.

‘They never stood a bloody chance, did they?’ said Murfin.

Fry glanced at him. His flippancy was gone, and he was sweating a little despite the draught stirring the curtains behind him. Of course, Gavin was a family man, with children of his own. There were some things that got to you, no matter how hard you tried to keep up the exterior.

‘They say it’s better to die of smoke inhalation than burn to death, anyway,’ she said, though she didn’t expect it to help. Her own flesh still crawled at the thought of the flames.

She looked away from Murfin before he could distract her concentration. This room had been packed with plastics, too – TV, video recorder, racks of CDs and DVDs, boxes full of children’s toys under a shelf in the corner. Most of the toys were just a molten mess now, multi-coloured pools of lava that had run on to the carpet and congealed in the spray from the firemen’s hoses. There were recognizable shapes here and there – the twisted controls of a PlayStation console, the burned edge of a Monopoly game. The head and one arm of a Barbie doll waved from a skin-toned puddle, like someone drowning in a sea of their own flesh. Something scorched and wooden gazed accusingly at her from blackened eyes.

Then a tiny flash of colour caught her attention. A glint of bright yellow, like a drop of sunlight in the blackness. She crouched towards the floor and gently blew away the ash. A broken section of Monopoly board lay at her feet: Piccadilly and the Water Works.

Of course, the untreated polyurethane foam in the furniture had been the real problem. Brian Mullen had definitely had a point. Lindsay could have spent her money more wisely if she’d replaced the cheap sofa instead of the carpet. The outcome really could have been different. For a start, her children might still be alive.

When she walked through into the kitchen, Fry found it almost pristine and untouched, apart from a few muddy footprints on the vinyl flooring. From the condition of the teak-effect units and the white painted walls, she would never have guessed there had been a fire at all. She felt as though she’d stepped out of one film set and into another, where an entirely different story was taking place. This one suggested a harmless domestic comedy – a family eating breakfast together in their spotless kitchen, Mum and Dad and the kids, all chattering and laughing, hurrying to get ready for work or school. Behind her, the other room might have been the scene of a cheap horror film, except the credits had already rolled and the crew had packed up and gone home.