They said I should have burned her with the rest of them. When everyone died I cleared this place out room by room, working for hours until every trace of dead flesh had been removed from the building. Except for her – the Swimmer.

        I found her a couple of days later, when she’d just started to move. I don’t know how I missed her before: poor bitch must have been about to take a dip in the pool when it caught her, and the doors had swung shut, trapping her inside. When I first found her she was shuffling about in the shadows like those on the other side of the boundary fence, constantly dragging herself from one end of the room to the other, backwards and forward, walking into walls and lockers, tripping over upturned benches and other obstructions. She looked pretty comical crashing around, stupid almost, but I wasn’t laughing. I was too scared. I still am.

        When the others got here we talked for hours about getting rid of her. Ginnie and Sean were dead against the idea of keeping her inside the building with us, even though there was no way she could get out into any other part of the hotel. Howard and Amir came around to my way of thinking pretty quickly: it made sense to keep watch on her – Christ, those bloody bodies had dragged themselves up onto their feet after they’d been lying dead for days. None of us knew what they might do next. The Swimmer would show us – in a perverse way she’s helped us to stay alive. Shut away in the changing room as she is, sheltered from the rest of the dead world outside, we’ve been able to watch her decay and change. She’s shown us how the dead have evolved – what they’ve become.

        The changes have been gradual; sometimes nothing happens for days, then she’ll react differently to one of us and we’ll know that the hundreds of thousands of bodies on the other side of the fence will soon be doing the same. None of what’s happened to the world makes any sense, but what’s happening to the dead makes the least sense of all: as they’ve continued to rot, so their control and coordination has somehow returned. It’s like they’re starting to think again, and make decisions. Sometime soon I’m sure they’ll reach the point where they’ve decayed to such an extent they can no longer keep moving – but when will that be? More to the point, what will they be capable of by then?

        It was a week after the day everyone died when I first realised she was watching me. For a week her movements had been uncoordinated, random – and then suddenly she could see and hear again. Her dark eyes stared back at me whenever I approached. And when Howard’s dog barked she reacted too; she lurched towards the window and hammered her hands against the glass as if she was trying to escape. As the days passed her reactions seemed to slow down. They became more deliberate and less instinctive. I realised she was regaining control.

        I’ve spent hours watching her since then. Sometimes it’s like I can’t take my eyes off her, even though she disgusts me. I’m sure I saw her here before she died; I remember a once-pretty round face, heart-shaped lips, slightly upturned nose and short, dark-brown hair flecked with highlights. Joanna, I think her name was. Her subsequent deterioration has been remarkable. Even in here, where she’s protected from the weather and the worst of the insects, I’m astonished at how quickly she has been reduced to a grotesque shadow of the person she once was. The colour of her flesh has changed from the white-pink of life to a cold blue-grey. Her skin has shrivelled in places and slipped in others. There are bags under her bulging eyes where her mottled flesh has sagged. Her body is almost turning itself inside out. Gravity has dragged her rotting guts down and now they’re dripping out between her unsteady legs. Even from the other side of the door I can smell the stench of her decay.

        It’s almost two months since this nightmare began. Recently the Swimmer’s behaviour has changed again. Perhaps it’s my imagination, but she seems more aware than ever now – not just more aware of me and the others but more self-aware too. I don’t know if she has any memory of who she used to be, or if she understands what she has become, but whatever she does or doesn’t know, a couple of days ago I swear I caught her trying to open the door. I found her leaning up against it, banging her right hand down on the handle repeatedly. She eventually noticed me standing at the window and stopped. She looked at me for a few seconds, then she stumbled back into the shadows. If she’d run at the glass I’d have been less concerned, but she didn’t: she actually moved away. She saw that I was watching her and she tried to hide.

        Yesterday afternoon, for a short time, she stood in the middle of the room looking back at me through the window. I couldn’t take my eyes off her grotesque face and I found myself wondering again who she might have been before she died. Does she see me and remember what she once was, or does she see me as a threat? Am I her enemy?

        I’ve begun to hate her. She’s one corpse in a world filled with millions, but because she’s in here with us, I’ve begun to focus all my pain and frustration directly on her. Sometimes I feel like she’s taunting me, and it’s all I can do not to destroy her. Yesterday when she was watching me I stood on the other side of the door with an axe in my hands for what felt like for ever. I wanted so badly to cut her down to nothing, batter her into memory.

        But I know I can’t harm her; we still need her.