Alex was dozing when she got the call. She hadn’t been able to settle in bed that night, turning beneath the duvet in a sleep-starved state before admitting defeat and getting up to instead set up camp beneath a blanket on the sofa. It occurred to her that this was how Chloe must have spent the past nine months, and that this was the reason she had been reluctant to live alone. Yet she knew that Chloe’s fear had existed on a scale she couldn’t comprehend. This feeling of anxiety took hold quickly and without reprieve, and she could only imagine how difficult it must have been for Chloe to attempt a normal existence after her attack. Not for the first time, she felt an increasing respect for her young colleague.

The officer who called her reported that a fifteen-year-old boy had been attacked in a lane just a few streets from his home. Petrol had been thrown at him, but the attacker had been interrupted by a passer-by before he had been able to ignite it, if that had been the intention. Given recent events, Alex feared it a certainty. The account given to her over the phone – a call that had been made much later than she was happy with – suggested that the boy was refusing to speak to anyone, least of all the police, but that was hardly surprising. The trauma of what had happened to him was likely to have stunned him into temporary silence.

Pulling on a pair of trousers, Alex wondered what the hell was happening to the world. Attacks such as this seemed to be on the rise, but the news reports that filled the TV and radio with an ever-increasing sense of bleakness at the state of mankind always consisted of stories plucked from other places: the big cities that lay miles from the supposedly sleeping hills of the South Wales valleys. People didn’t expect incidents such as this to occur on their doorsteps, and when they did, they were all the more shocking for it.

Fifteen, Alex thought as she searched her jacket pockets for her car keys. Just a kid. Why would anyone attack a kid like that?

Making sure she had her mobile phone with her, she pulled the front door shut behind her, locked it and made her way out into the night. Recent temperatures had been unusually mild for the time of year, but during the past few days a chill had kicked in and winter seemed to be making its first appearance. Beneath the glow of a street lamp, Alex unlocked her car and got inside, turning the heater up as soon as she started the engine. Her thoughts strayed once again to the homeless man found in the derelict hospital, murdered and still to be identified. Had he been sleeping rough for some time, or had he only just been made homeless? Someone must have known him well enough to have missed him at some point.

As she pulled the car from the kerbside, she mulled over the recent incidents. The fire at the Hassan shop. The blaze at the old hospital in which a man had been killed. And now the teenage boy doused in petrol. Were the three linked? The use of petrol made it too coincidental – the time between the incidents too brief – for the events not to be connected in some way.

The boy had been taken by ambulance to the Royal Glamorgan Hospital in Llantrisant, where uniformed officers had spoken with his mother. His physical injures included a fractured wrist and bruising, but Alex knew the psychological impact of the incident would stay with him for much longer. The officer she had spoken with had told her the boy was autistic, although few further details had been given. She wondered the extent to which he was affected; she knew little about autism, but assumed it would inevitably impact upon the boy’s ability to comprehend and cope with the assault.

As she approached the end of her street, Alex put her foot to the brake. Nothing happened. She wasn’t doing much of a speed, but it was night-time, the street was quiet and the hospital was a half-hour’s drive away, so she was going faster than she usually would. She tried the brake again, pushing the pedal flatter to the floor in an attempt to slow the car. The end of the street neared and she felt herself begin to panic. She pumped the brake with her foot, but still nothing happened.

As she closed upon the junction that connected the end of her street with the main road that snaked up the side of Caerphilly Mountain, Alex yanked the handbrake. It slowed the car, but not enough to stop it pulling out onto the main road. She swung the steering wheel in the hope of getting out of the path of any oncoming traffic, but the glare of lights from a car racing up the mountain road told her she was too late.

The other car was going too fast to stop. Alex pushed herself back against the driver’s seat, bracing herself for the inevitable collision. There was a screech of tyres and a crunch of metal against metal as the back of her Audi was smashed into and the car careered into the front wall of one of the gardens opposite.