I am still shaking when I wake up, stiff and uncomfortable, on the sofa. It has been two days since my biopsy and I haven’t been to bed yet. Each time I sleep it seems I fall back into Callie’s memories and I’m scared of what I might see when I close my eyes. I’m scared of the darkness of my dreams. The things I can’t always remember as I wake, sweating and screaming. The finer details fading, slipping just outside my consciousness once more, and all I’m left with is a thick coating of fear.

‘I’d hate for YOU to have an accident’ the text to my phone had said, and I know if I take it to the police I will be dismissed again. There’s no way of knowing who sent it and it’s so carefully worded it may not be interpreted as a threat – but I know it is – and despite my incessant checks the front door is locked, the chain is across, the furniture I’ve dragged in front of the door hasn’t moved, every little sound I hear I convince myself someone is here with me.

I try to stay awake with perpetual cups of coffee, pacing the flat, studying my mind map, endlessly Googling. It’s been ten days since the body was discovered at Burton Aerodrome – why haven’t the police identified it yet?

Who was in my flat? The local news hasn’t reported any other burglaries the past few days and I wonder whether mine could somehow be connected to Tom and Amanda’s break-in. I go back to the day of Callie’s funeral and check the archives around that time. It takes hours of reading until I find it. A small paragraph reporting the break-in and then days later a follow-up.

Below is a photo of Amanda’s ruby and diamond star necklace. Neither of the men named are Neil or Owen and I think Tom’s break-in was probably unconnected to Callie, but what about mine? My mind keeps flicking to the message on my fridge.

‘Stop Digging’

Oh God. I’m so scared.

As dawn begins to break I slump on the sofa, staring blankly at the TV glowing in the corner, the sound down low so I can hear if anyone tries to get into my flat again. Listening. I’m always listening.

One hundred and eighty-four days ago Callie’s heart was transplanted into my body. Sometimes now I hate her, this girl who allowed me to live. I don’t know what she wants. What she’s trying to tell me. I don’t know what’s real any more and what isn’t, and there’s no one I can talk to. No one I can trust.

Outside the window the sun rises gold but even in the first twinges of daylight I still feel it. The prickling sensation of eyes on me. Watching me. Waiting. And I stalk around the flat again. Checking inside the wardrobe, behind doors, under the bed but there isn’t anyone there. There never is.

There’s a thickness in my throat as I swallow down my medication. My nose is streaming and my forehead is burning. I’m dying. The thought pops into my mind unbidden and I push it away. Of course I’m not. But what if I am? What if my body is starting to reject Callie’s heart and I never find out what happened that night for Tom and Amanda? I cradle my heavy head in my hands. Despite the warnings I have received I have to try again but I don’t know which way to turn.

In the kitchen, I study the mind map, and as the sun shifts in the sky it reflects in the silver of the fridge handle. The dazzling brightness triggers a memory, mine this time, of the first visit I made to Nathan’s house, pulling the garden chair cushions from Nathan’s shed, upsetting the flowerpot. That glint of silver before I ran from the spider. A door key.

* * *

I step into Nathan’s hallway and lock the front door behind me, slipping the key inside my pocket. I’ll put it back in the shed before I leave. The house is still. Quiet. But I find the silence oppressive rather than reassuring. Although I know there’s no one here, Nathan is at work, I only crack the lounge door open a fraction before squeezing through and I tiptoe towards the window. Dropping my bag, I hook back the curtains and peep out onto the street. I count the ways this could go wrong but although an air of unease hovers over me, there are no neighbours pointing at the house, talking worriedly into mobile phones. I don’t think anyone saw me come in, and after I few minutes I feel calm enough to move. I don’t know what I hope to find here but I feel both excited and scared; my pulse is rapid and light.

I have never been upstairs before; we never made it from the sofa to the bed that night, and as I remember what we did, his hands on my body, I swallow down bile. On the landing there are three closed, glossy white doors in front of me and I push the first one slowly open. It’s the bathroom, smelling faintly of bleach. I scan the room taking in the wicker laundry basket in the corner, the blue tiles around the bath. It’s exactly as I had dreamed it and, if I had a smidgen of doubt before, I am now as certain as I am of my own name that my dreams are Callie’s memories. I open the mirrored bathroom cabinet but there’s no box of tampons, no Veet, just Nathan’s lonely razor and some aftershave.

The bedroom is next; the tall oak wardrobe stands in the corner where Callie pulled her overnight bag from in my dream. So she did want to leave Nathan. I sit heavily on the end of the neatly made bed, quilted throw hanging even and straight and think about the texts she sent to the unknown person. It seems likely she was having an affair, and Nathan found out and hit her, and I wonder if it was the first time or if he’s beaten her before? He doesn’t look like a violent man. ‘Attentive’, Tom called him. But I think there’s probably a fine line between being attentive and being controlling, and it seems Nathan crossed it. If he hadn’t emptied their savings account she’d probably have left him sooner and the thought she might still be alive saddens me, conflicting with the knowledge that if she were still here, I probably wouldn’t be. She was probably on her way to meet her lover when she died, perhaps the payday loan she’d applied for had come through and she was dreaming of her happy every after. But I’m only speculating, and even if I had definite proof I know I can never tell Tom and Amanda their daughter was unhappy with Nathan, and I feel I’ve failed them somehow. My thoughts race and my head throbs. I press my hand against my forehead. It comes away hot. I should go home. I’m really not feeling well but I can’t help wondering who Callie was sleeping with: if it was Owen, if he was a friend of Nathan’s. I rummage through the wardrobe and chest of drawers, not quite sure what I’m hoping to find, but there’s no clutter to sift through, just clothes crisply pressed and folded.

The third bedroom is just as neat. Orderly. Housing only a single bed and a wooden blanket box. I lift the lid and I’m greeted with an array of brown padded envelopes. I tip out the contents of the first one. It’s a pile of Valentine’s cards and ‘I love you’ notes and I feel desperately sad as I read them. Callie and Nathan were happy once. The next envelope is bursting at the seams and as I look inside I am shocked to see bundles of cash bound together with elastic bands, and as I pull them out I see something else at the bottom of the envelope that glints in the light. It’s a necklace: rubies and diamonds shaped like a star. It’s the pendant that was stolen from Amanda during the burglary on the day of Callie’s funeral. Why would Nathan have this? I remember Tom telling me Nathan didn’t go to the wake, but surely he wouldn’t have broken into Tom’s house? The next envelope is light, and at first I think it’s empty but my hand pulls out three passports, and I flick to the photos in the back. There’s one for Nathan, one for Callie and one for Sophie. Sophie, who is supposed to be in Spain? How can she be there if her passport is here? Nathan must know she’s not abroad. Why’s he lying? Why hasn’t she been in touch with her parents? A thought hits me hard. What if the body in the airfield is Sophie’s? Is that what Callie has been trying to tell me? Just how dangerous is Nathan? There’s a sick feeling in my stomach as I bundle the passports back into the envelope, and they slip from my fingers as I’m startled by a crashing sound. The garden gate. I scoop everything from the floor and shove it in the box and I hold my breath as I wait, hoping for the rattle of the letter box as junk mail is pushed through. A key scrapes the lock and a draught shoots upstairs as the front door opens. Nathan is home. I look around the room wildly. There’s nowhere to hide. And then with a sinking feeling I remember.

I left my handbag in the lounge.