When Becky arrived at the scene at two minutes past eight, the DI of the team handing over the case was already there, pacing up and down outside the house in the cold February air, looking at his watch.

She struggled her way out of her car and walked up the short drive towards the house.

‘Why is it still a crime scene?’ she asked after introducing herself. ‘Hasn’t it been processed yet?’

‘Yes, but as it’s being passed to you, we thought you might want it preserved as far as possible before we cleared out.’

‘Thanks, that’s good of you. Shall we get inside out of this miserable weather?’

A uniformed officer unlocked the door and they stepped into the hall.

‘I think we should start in the kitchen,’ the DI said. ‘It looks as if that’s where it all began. It’s through here.’

He pushed open a door into what appeared to be the living room, with a comfortable-looking sofa and two armchairs, and strode towards a door in the far corner, presumably leading to the kitchen.

Becky took two steps into the room, stopped and looked around. Already the scene wasn’t making sense to her. It seemed to be a home that had once been cared for. There were pictures on the walls, books neatly arranged on shelves, an assortment of multicoloured cushions that appeared to have been chosen with care. And yet a smell of unwashed bodies, dirty pots, unemptied kitchen bins and general grubbiness hung over the place. Had they just stopped caring about their home?

I slip my key into the back door and turn it, praying it isn’t bolted on the inside. Ian had rarely bothered, saying that no one could get round the back anyway. I sigh with relief as the key turns easily, and within seconds I am in.

The concrete floor of the rear porch is freezing underfoot, and I spot a couple of pairs of boots and some trainers by the door. The boots would be warmer, but the trainers are probably going to be the most practical. There’s a coat hanging up too, and I definitely need that. For now, though, the bathroom is calling.

The downstairs toilet was put in at the back of the house by the previous owners, who loved to garden. It saved them trudging through the house all the time, but it is a cold and unloved area. I always intended to decorate it, put something down on the bare floor and change the door so that it closes properly, but I hadn’t been able to afford it. For now, though, it is perfect.

Just as I am about to pull the chain of the old-fashioned toilet I hear a noise. I don’t move. My hand is still grasping the porcelain handle. Someone is talking. Someone is in my kitchen.