‘Lex, there are seventeen thousand students at Durham – there’s always someone behind you.’
‘This is different. They’re trying not to be seen.’ Lexi spoke in an urgent whisper, Kelly straining to hear every word. ‘When I turned round just now there was no one walking, but they’re there, I know it.’
‘You’re getting yourself in a state. Give me a call when you get home, yeah?’
Kelly had been getting ready to go out, she remembered. She’d cranked the music up as she did her hair; threw another rejected dress on the pile at the end of the bed. It never crossed her mind that Lexi hadn’t called, until her mobile had rung with a number she hadn’t recognised.
‘Kelly Swift? This is DC Barrow-Grint from Durham police. I’ve got your sister with me.’
‘It wasn’t your fault,’ Nick said gently. Kelly shook her head.
‘He wouldn’t have attacked her if I’d stayed on the phone.’
‘You don’t know that.’
‘If he had, I’d have heard – I’d have been able to call the police straight away. It was two hours before Lexi was found – she’d been beaten up so badly she could hardly see – and by that time the offender was long gone.’
Nick didn’t contradict her. He turned his coffee cup around in its saucer until the handle was facing him, cupping both hands around it. ‘Does Lexi blame you for what happened?’
‘I don’t know. She must do.’
‘You haven’t asked her?’
‘She won’t talk about it. Hates it when I do. I thought she’d be affected for months – for ever, even – but it was as though she just drew a line under the whole thing. When she met her husband she sat him down and said “There’s something you need to know”, and she told him the whole story then made him promise never to mention it again.’
‘She’s a strong woman.’
‘You think so? I don’t think it’s healthy. Pretending something didn’t happen isn’t the way to deal with a traumatic event.’
‘You mean, it’s not the way you deal with traumatic events,’ Nick said.
Kelly looked at him sharply. ‘This isn’t about me.’
Nick drained his coffee and set the cup carefully on the saucer before looking Kelly in the eye. ‘Exactly.’
Kelly’s mobile rang as they returned to work. She hung back at the top of the stairs, avoiding the noise of the busy MIT office. It was Craig, from the CCTV hub.
‘Kelly, have you seen BTP’s internal briefing today?’
She hadn’t. It was hard enough to keep up with the volume of emails relating to this job, without reading her own force’s daily missives.
‘The CCTV room here has been compromised. Given what you told me the other day about your Met job, I thought I should give you a ring.’
‘A break-in?’
‘Worse. A hacking.’
‘I thought that was impossible?’
‘Nothing’s impossible, Kelly, you should know that. The system’s been sluggish for a few weeks; we called an engineer and when he came to take a look he identified some malware. We’ve got a firewall in place which makes it nigh-on impossible to be hacked over the web, but doesn’t stop someone physically introducing viruses to the system.’
‘An inside job, then?’
‘All the staff were interviewed in turn this morning by the superintendent, and one of the cleaners broke down. Said she’d been bribed to carry a USB stick in and put it in the main computer. Of course she claims to have had no idea what she was doing.’
‘Bribed by whom?’
‘She doesn’t know his name, and conveniently doesn’t remember what he looks like. She says she was approached on the way to work one day and offered more than a month’s salary for a few minutes’ work.’
‘What’s the extent of the hacking?’
‘The malware introduces a programme which talks to the hacker’s computer and replicates the entire system. They can’t control the camera direction, but the bottom line is whatever our control room sees; the hacker can see.’
‘Oh my God.’
‘Does it fit with what you’re dealing with?’
‘It’s certainly possible.’ Despite her good working relationship with Craig, Kelly was mindful of what Diggers might say, if she were to release any more information than necessary. The last thing she needed was another telling off, although there was no doubt in her mind the two jobs were related.
‘Our offender’s been using London Underground’s own cameras to stalk women,’ Kelly announced, walking into the office and interrupting a conversation Nick was having with Lucinda. She filled them in on the call from Craig. ‘BTP’s Cyber Crime unit are there now, but although they’ve identified the malware, it’s less straightforward to eradicate it.’
‘Couldn’t they switch off the whole system?’ Lucinda asked.