‘No worries, shame you couldn’t stay longer. Still I’ve got your number, maybe we can try another night?’ She gave him a half-smile and said something utterly noncommittal, walking out of the pub before he could say any more.

Jessica couldn’t sum up the way she was feeling. There was some sort of elation that she hadn’t just been paranoid, but sadness she hadn’t figured any of it out before Carrie had died. Then there was the realisation she still didn’t have the proof she needed. She had a broken phone under her bed and the second-hand word of someone who worked at the prison. She still had to figure out how it happened too. Farraday could have met Donald McKenna in prison and somehow smuggled blood and hairs back out again but it wouldn’t have been easy.

Then another idea struck her, something she should have thought about when she was on the train earlier. Adam told her a twin had to be identical to share DNA but what if one of them changed their appearance? Could it be possible that somewhere along the line her boss and McKenna were direct relations but one of them had altered the way he looked? It was unlikely but surely more of a possibility than tunnelling out of a maximum-security prison? The more Jessica thought about it, the more she was convinced. They were around the same age, same height and same build. As she reached her car, she took out the piece of newspaper from her pocket and stopped under a nearby street light to look at the photo of the DCI. She tried to remember what McKenna looked like. Surely it was like this? Surely?

She could feel the itch in the back of her head again. ‘It’s him. You’re right. You were always right.’ Jessica knew she wasn’t heading home. She drove to the estate Farraday lived on and parked where she had done in the previous days, a couple of streets away. She hadn’t changed her clothes all day and was still wearing the suit she’d had on at the women’s prison and for the train journeys. The nights were beginning to get cooler but Jessica didn’t want to miss anything, shivering as she got out of the car and walking the short distance to sit on the wall opposite the chief inspector’s house. Behind the low row of bricks was a large hedge which meant no one from the house behind could see her and she could push back into the greenery to avoid being seen easily from the front. On a night like this, it also offered a small amount of protection from the cold.

She sat on the wall, leaning backwards, eyes fixed on the house in front of her. She eyed the gate she had jumped over and hurt her ankle. It was as imposing as ever and, as she squinted into the darkness, Jessica could see a car parked on the driveway. She let her mind run away with her.

‘The garage is being used for something sinister. Just go and look.’

There were lights on downstairs and Jessica fixed her eyes on the illuminated rooms, looking for silhouettes or clues of anything that might be untoward.

How could she prove it was him?

A light breeze whipped across her and Jessica edged backwards into the shrub. She could feel its spiky branches pushing into her back but it was more appealing than the cold. An owl hooted somewhere nearby and Jessica found herself looking around for the source of the noise before cursing herself for taking her focus away from the house.

‘Don’t look away, you’ll miss something.’

She flicked her eyes back towards the building and tried to see if anything had changed, remembering the spot-the-difference puzzles she used to do as a kid. The car hadn’t moved and the light was still on in the same downstairs room but had someone moved a curtain? She blinked to test that her eyes were working fine. It wasn’t that late but Jessica knew she couldn’t risk moving. With her watching the house, the chief inspector couldn’t leave and no one else could be killed.

As she moved her focus towards the gate, Jessica felt the blinks lasting longer until, finally, she could resist them no more.

Jessica jumped as the sound of a car’s engine roared past. She went to move her arms but one of them was full of pins and needles, the other wedged tight. Opening her eyes to see a tangle of leaves and branches, Jessica jolted upwards, knowing where she was but not quite believing she had let it happen. It was light and cool so she knew it must be morning. She had somehow slept for the whole night in the small gap between the wall and hedge opposite DCI Farraday’s house.

She squeezed her way up and looked over the top of the wall. The chief inspector’s gates were still shut but there was no car in the drive. Jessica banged her hand on the edge of the bricks to try to get some feeling back into it before pulling out her phone and checking the time: 07.41.

Jessica could feel the pain had returned to her ankle and grimaced as she put her weight on it, hauling herself back onto the pavement. She tried to run but could only hobble back to her car. In her mind she knew she had let another victim down; she had fallen asleep and that meant the DCI had been free to leave the house the night before. She was trying to calm the panic rising in her as she reached her car, fumbling in her jacket pocket for the keys. Her hands were grubby and she could see dirt stains on her trousers but there was something far more important than all of that.

She unlocked the car door and threw herself into the driver’s seat, starting the engine and tuning the radio to the local talk station. If there had been another killing the night before, it would definitely be a big story. She knew she hadn’t missed any calls but maybe it was because they were waiting for her to get into the station?

Jessica crunched the car into first gear and turned around in the road, heading towards the station. The two radio presenters were joking about something irrelevant and she swore at them to get to the news. Eventually, when she was just a few minutes from Longsight, the jingle kicked in and the newsreader started to speak. Jessica turned the volume up but they were talking about football. She took a hand from the steering wheel to rub her head. Something wasn’t right but maybe they just hadn’t been given the story yet? That made sense.

She pulled into the station and parked at an angle in one of the bays but didn’t want to waste time straightening out. She hurried through the front entrance, heading to the front desk.

‘Are you all right?’ the desk sergeant asked.

‘Yeah, yeah. What happened overnight?’

The man looked confused. ‘Um, nothing in particular – a domestic violence call-out, a bit of vandalism. The usual. What are you looking for?’

It was Jessica’s turn to be puzzled. ‘That’s all?’

‘Yes . . . are you sure you’re okay? You look a bit, um . . .’

Jessica ignored him, moving quickly around the counter towards the female toilets. She pushed through the door and went quickly to the sinks, putting together the pieces of what had happened in the past few hours. It barely seemed believable but, after hearing Farraday’s name, she had driven to his house, sat on the wall opposite watching him, slept in a hedge and then, for some reason, convinced herself someone else had been killed in the meantime.

Were those the actions of someone thinking clearly?

Jessica looked at herself in the mirror, staring into her own eyes and wondering what was happening in her head. There was a scuff of dirt on her right cheek and, as she reached up to wipe it away, she saw just how filthy both of her hands were. As she looked closer, Jessica could see there were a couple of small twigs lodged in her hair and one was stuck to her suit jacket.

She took deep breaths as she cleaned her hands and face, trying to get as much soil from her suit as possible. All she could think of was DCI Farraday. He must have left all the clues because he knew whoever found them wouldn’t be able to prove anything.