It was early evening. They had been basking in a week of unfamiliar sunshine and the warmth of the day was still such that Leah had forgotten to take a jacket with her when she left to go out. She hadn’t really been thinking straight when she’d shut the door on the house in Treforest. Her mind was a meld of Keira, Leighton, Tom: of all the things she was losing any sense of control over. Everything was falling to pieces around her and she felt powerless to stop it. She didn’t like feeling powerless.

She caught a train to Llandaff in Cardiff and walked from the station through the park. It was busy that day, packed with families and groups of friends whiling away the last warm hours of the summer evening. Cyclists, joggers, dog-walkers, parents pushing prams … She passed countless faces, and yet she had never felt so lonely. She wondered how any of them might react if she was to say to them, ‘My friend died on Sunday. Murdered, they think. I miss her.’ She wondered if anyone would care.

This was the thing: no one did care. Everyone was living their busy lives with their busy careers and their busy families, and no one really had much time for anyone else even if they pretended the opposite. Leah was on her own, yet no one else appeared to be. Everyone else seemed to form part of a unit. Everyone else seemed to be connected somehow, while Leah could feel herself isolated, floating. She didn’t belong anywhere, to anyone.

She had always believed she didn’t want to, but she had been lying to herself.

She left the park and headed out onto the main road, busy with slow-moving evening traffic. She had purposely taken the long route round, hoping to build courage before reaching her destination. She had known where he lived for a while now – she had checked the driver’s licence in his wallet when he’d been out of the room once – but she had never yet felt the need to go to his house, not in the way she felt it now.

She’d searched for the house on Google Maps. It had been pretty much what she’d expected: a large semi with a driveway and a neatly tended garden that looked as though someone else was paid to manage it. From what she’d seen of Leighton’s wife, Melissa, Leah didn’t think she was the type to get her hands dirty. And she knew they had money, presumably plenty of it. Enough to hire a gardener. Probably a cleaner too. Leighton earned a good salary as a lecturer at the university, and he’d made a bit from his novels, though likely nowhere near the amount Leah imagined he’d hoped for. She didn’t think he’d still be at the university if he had.

Then there were the other houses he owned: the ones he rented out to students just like her. She’d heard him talking about it to his wife once, the pair of them arguing over the phone about unpaid rent and a door that needed replacing after a drunken argument between two housemates resulted in the police being called. Leighton hadn’t heard Leah at the door of his office; he didn’t know she’d been standing there listening. Leah had wondered then if Leighton loved his wife. She still wondered about it now.

Melissa ran a beauty salon in the city centre, one of a small chain dotted around South Wales. Between them, she and Leighton must be worth a bit. Leah had been to the salon once, had booked in for a haircut. Once inside, she had changed her mind at the last moment. Melissa had been there, talking with another customer behind her as Leah had sat and watched them in the mirror. Designer clothes, nice make-up, expensive perfume that lingered in the air long after the person was gone … What did these women have to worry about? she thought. Nothing. One day, she was going to be just like them.

She recognised the house when she was still some distance away: its red-brick facade and its old-fashioned tiled roof. This area of Llandaff was like another world: no graffitied walls and upturned wheelie bins here, just expensive sports cars and pointless 4x4s that no one who lived in a city really needed. She felt it in her gut, a familiar twisting, burning sensation; the same one she could remember experiencing throughout most of her life.

She wondered whether both of Leighton and Melissa’s daughters lived with them. The younger of the two was sixteen, so presumably still at school. The older was about Leah’s own age, which made what Leighton had done all the more despicable.

Approaching the house, she felt a chill. She had never before been this close to his home, this close to his family. There was a faint flurry of excitement intermingled with the anxiety she felt in the pit of her stomach, but mostly just a nauseous feeling: a sick-to-the-stomach, no-turning-back-now sensation.

She crossed the road so that she’d be on the same side of the street as the house. She imagined herself for a moment trying the front door, finding it unlocked; walking through the hallway and into the kitchen, where the family would be at the table eating dinner. She would take a seat next to Leighton’s wife and introduce herself; say, ‘You don’t know me, but …’ Wait to see the look on all their faces – his in particular – when she exposed him to his family. The thought warmed her; she forgot the previous chill of nerves that had spread through her.

She stopped as she saw a car pull onto the driveway. A woman was driving; a pretty, blonde-haired woman whose face she was already familiar with. Melissa Matthews. Leah slowed her pace, giving the other woman time to get out of the car. She watched as Melissa went to the boot and opened it, then she reached for her mobile phone from her pocket and hurried her step again.

She lingered at the entrance of the driveway, looking up at the house and then back to her phone. As she’d hoped, Melissa sensed her there and turned. She was struggling with the heavy bag of shopping she was unloading, but persevered, yanking it onto the edge of the boot before lowering it to the ground. When she turned to look again, Leah was still there.

‘Can I help you?’

‘Is this number sixty-three?’ Leah asked.

Melissa nodded. She left the shopping where it was and took a couple of steps down the driveway. Leah felt her heart begin to thump beneath her T-shirt.

‘I’m looking for Sarah Davies,’ she lied, glancing back at her phone as though to check the non-existent address her recently invented friend had sent her. She hoped there was no one who went by the same name living in either of the houses next door, thinking now that she might have been better off picking a less generic name. She could feel Melissa’s focus fixed on her face, presumably on the bruising on her cheek that had been left by Jamie’s drunken punch. ‘Sixty-three Acorn Drive,’ she said, looking up to meet the woman’s eye.

Melissa smiled. She was pretty, Leah thought again; very pretty. She had one of those faces people turned to look at, men and women alike. Why wasn’t this woman enough for him? It didn’t seem to matter what some people had. They always wanted more. Leighton Matthews was obviously one of those people.

She felt jealousy rip through her, clenching her gut in a way that had become so familiar.

I’m outside your house, she texted, returning her concentration to her phone as though messaging the friend who didn’t exist. Your wife is nice.

‘This is Acorn Way,’ Melissa said, looking almost apologetic, as though she felt somehow responsible for Leah’s wasted trip.

Leah rolled her eyes. ‘What an idiot I am,’ she said. She gestured to the phone still in her hand. ‘I’ll give her a call now – find out where I’ve gone wrong.’

She looked up and past Melissa’s shoulder. There on the doorstep, frozen by the sight of her, was Leighton. His tall frame filled the doorway. His eyes were fixed to them, watching the exchange taking place. Leah gave him a smile before redirecting it to Melissa.

‘Thanks,’ she said. ‘Sorry I interrupted you.’

She turned and headed back the way she had come, her step now energised by a new-found confidence. She was capable of so much more than people thought. She was underestimated. She had spent her whole life being underestimated.

Whatever else she might be, Leah thought, she wasn’t going to be forgotten easily.

Once she was far enough away from the house, she stopped and returned her attention to her phone.

Tell her, or I’m going to.