The industrial estate, where the storage facility is housed, makes me think of a nuclear fallout zone. Large corrugated-iron buildings loom ominously in front of me as I try to decipher the labyrinthine map on the entrance gate. According to the map the storage units are in the yellow quadrant towards the centre of the estate. As I make my way across I take out my inhaler. I’m utterly exhausted and I haven’t even got there yet.

Eventually I see the name of the unit and a set of automatic glass doors with RECEPTION written above in big yellow letters. When I step inside I see a young woman in a navy-blue uniform sitting behind a desk. As I approach, my eyes are drawn to the badge on her lapel which says: ‘My name’s Kelly and I’m here to help.’

‘Hi,’ I say. ‘Could you tell me where …’ I pause to consult the piece of paper Sharon gave me. ‘Where Unit 428 is, please?’

‘Sure,’ she says, taking a leaflet from the front of the desk and opening it out. ‘This is a map of the Yellow Bay. The four hundreds are situated on the fourth floor.’

She takes a red pen and circles the relevant place on the map.

‘Your best bet is to take the lift, which is just over there,’ she says. ‘Then once you get to the fourth floor you need to turn right and you’ll find the even-numbered units.’

‘Thank you,’ I say, taking the map. ‘You’ve been really helpful.’

I go to the lift and press the button. As I wait for it to arrive I feel an odd sensation in the pit of my stomach. I have no idea what is waiting for me up there.

Then the lift doors open with a jolt and I step inside. I press the button for the fourth floor and close my eyes. I have never felt so strange. The anxiety, which had felt like sharp needles stabbing my skin, has been replaced with an odd sense of remove, like I am watching myself from above.

Everything that I have learned these last couple of days – Freya Nielssen, Sean’s accusations, the phone call from Ben – it all feels like it’s happened to someone else. I should be feeling horrified or upset. Instead I just feel numb.

After a couple of moments the doors open and I step out into a narrow corridor. The walls are painted an acidic yellow and the carpet is bright blue. The clashing colours make me feel disorientated. I turn right and count down the numbers on the metal doors.

420, 422, 424, 426 …

428.

I stop outside the door. There’s a small square pad in the centre of it. I take the fob out of my pocket and hold it against the pad. A green light flashes. I push the door open and step inside.