It seems an eternity until we see Katie appear on the CCTV image. She doesn’t pause, but she looks up at the camera as she approaches, staring straight at us until she passes underneath the camera and out of view. I see you, I mouth. I’m with you. I can’t stop my tears falling.
‘We can’t follow her through the ticket barrier, unfortunately,’ Melissa’s tone is companionable – chatty, almost – as though we’re working on a project together. It’s unnerving, more so than if she were shouting at me, or threatening me. ‘But we’ll pick her up again once she’s on the platform.’
She moves her mouse across the screen and I catch sight of a list of what I assume must be cameras: Aldgate East – entrance; Angel – entrance; Angel – southbound platform; Angel – northbound platform; Bakerloo – ticket barriers … The list goes on and on.
‘Quite a few of the early profiles aren’t in the right area for the cameras I can access,’ Melissa explains, ‘but we’ll be able to get most of Katie’s commute. Look – there she is.’
Katie is standing on the platform, her hands thrust into her pockets. She’s looking around and I hope she’s searching for cameras, or working out which of her fellow passengers might be a threat. I see a man in a suit and overcoat approach her. Katie steps back slightly, and I dig my nails into my closed palms until he passes without checking his pace. My heart is pounding.
‘Quite the little actress, isn’t she?’
I ignore her. The Overground train arrives and Katie steps on, the doors closing and swallowing her up all too quickly. I want Melissa to click on to the next camera, but she doesn’t move. She picks a piece of cotton from her jacket and frowns at it, before letting it float from her fingers on to the floor. My fantasy evolves: I imagine Simon returning from his interview; finding the house empty – the door unlocked – and somehow knowing I am next door. Rescuing me. My imaginings grow in detail and absurdity in inverse proportion to my dwindling hope.
No one is coming.
I will die here, in Melissa’s house. Will she dispose of my body, I wonder, or leave me here, festering, for Neil to find when he returns from his work trip?
‘Where will you go?’ I ask her. She turns to look at me. ‘Once you’ve killed me. Where will you go?’ She starts to say something – to deny that I’m going to die – then she stops. There’s a flash of what looks like respect in her eyes, and then it’s gone. She shrugs.
‘Costa Rica. Japan. The Philippines. There are still plenty of countries without extradition agreements.’
I wonder how long it will take them to find me. Whether Melissa could make it to another country by then. ‘They’ll stop you at passport control,’ I say, more confidently than I feel.
She looks at me scornfully. ‘Only if I use my own passport.’
‘How—’ I can’t find the words. I have stumbled into a parallel universe, in which people wield knives and use fake passports and murder their friends. I suddenly realise something. Melissa is clever, but she’s not that clever. ‘How did you learn all this?’
‘All what?’ She’s distracted, tapping the keyboard. Bored with the conversation.
‘The CCTV, a false passport. PC Swift said the adverts were placed by a man; that he had a mailbox set up in his name. The website is untraceable. You had help – you must have done.’
‘That’s rather insulting, Zoe. I think you underestimate me.’ She doesn’t look at me, and I know she’s lying. She couldn’t have done this alone. Is Neil really away with work? Or is he upstairs? Listening. Waiting until reinforcements are needed. I glance nervously towards the ceiling. Did I imagine the creak in the floorboards?
‘That’s been fifteen minutes,’ Melissa says abruptly, looking at her watch. ‘I can’t get into the Overground trains, but the next camera will get her changing at Canada Water.’ She clicks on the next camera and I see another platform; a group of schoolchildren being shepherded away from the edge by three teachers wearing high-visibility tabards. A train arrives and I scour the screen for Katie, but can’t find her. My heart beats faster: has something happened to her already? On that short journey from Crystal Palace to Canada Water? But then I catch a glimpse of a white Puffa coat, and there she is, her hands still pushed into her pockets, her head still turning this way and that, looking at everyone she passes. I let out the breath I’ve been holding.
Katie goes out of sight, and despite Melissa bringing up two more cameras, we don’t see her again until she’s waiting on the Jubilee line platform. She’s standing close to the platform edge and I want to tell her to step away, that someone could push her in front of the train. Watching her like this, on CCTV, is like watching a film in which you know something terrible is about to happen to the main character, and you scream at them not to be so stupid.
Don’t go outside, don’t ignore that sound you heard … haven’t you read the script? Don’t you know what happens next?