Erika realised she was lucky, though, and blessed in comparison. Had Tatiana, Mirka, and Karolina said goodbye to family just like she had? Erika remembered the crumbling bus terminal in Bratislava: rows and rows of bus platforms. Each platform had rusting metal poles holding up an enormous long shelter, and it had been so damp. She had wondered if it was damp from the tears of all those teenagers who had to say goodbye, to leave a beautiful country where the only way to succeed is to get out.

Did the parents of the three dead girls cry? They had not known that their girls would never return. And what had happened when the girls arrived in London? How had they ended up working as prostitutes?

Tears rolled down Erika’s face, and when the waiter came to take her coffee cup, she turned her head away and angrily dried her eyes.

She had cried enough tears to last a lifetime. Now it was time for action.

36

The next afternoon, Erika felt like she had exhausted all the options she could take as a civilian. She was making another cup of coffee and weighing up her options, when she heard a bell ringing. It took her a few moments to realise it was the front door. She left her flat and went down to the communal front entrance. When she opened the door, Moss was waiting on the front step, her face giving nothing away.

‘Are you making home visits?’ asked Erika.

‘You make me sound like a bloody Avon lady,’ said Moss with a wry grin.

Erika stood aside to let her in. She hadn’t expected to ever receive visitors in the flat, and had to clear off the sofa for Moss. She grabbed several days’ dirty plates off the coffee table, and the teacup overflowing with cigarette butts. Moss didn’t comment and sat down, shrugging off a backpack she was carrying.

‘Do you want some tea?’ asked Erika.

‘Yes please, boss.’

‘I’m not your boss anymore. Call me Erika,’ she said, tipping the dirty plates into the sink.

‘Let’s stick with boss. First names would be weird. I wouldn’t want you to call me Kate.’

Erika stopped, her hand hovering over a box of teabags, ‘Your name is Kate Moss?’ She turned to see if she was joking, but Moss nodded ruefully. ‘Your mother called you Kate Moss?’

‘When I was given the name Kate, the other, slightly thinner . . .’

‘Slightly!’ laughed Erika, despite herself.

‘Yes, the slightly thinner Kate Moss wasn’t a famous supermodel.’

‘Milk?’ said Erika, grinning.

‘Yes, and two sugars.’

She finished making the tea whilst Moss busied herself pulling paperwork from her backpack. Erika came over with mugs and biscuits.

‘That’s a good cup,’ said Moss, taking a sip. ‘How did you learn to make such a good tea? Not in Slovakia?’

‘No, Mark, my husband. He ingrained in me the tea ritual, and so did my father-in-law . . .’

Moss looked uncomfortable that she’d led the conversation down this path. ‘Shit, sorry, boss. Look, none of the team at the station enjoyed reading about . . . about, well, you know. And we didn’t know about . . .’

‘Mark. I’ve got to start talking about him sometime. When you lose someone, not only are they gone, but everyone around you doesn’t want to talk about them. It drove me slightly crazy. It was like he’d been deleted . . . Anyway, why are you here, Moss?’

‘I think you’re on to something, boss. Isaac Strong sent some case files over. DCI Sparks is refusing to see the link, but there were three young girls killed in similar circumstances to Andrea and Ivy. All three found in water with their hands bound, hair missing from their scalp. They’d been strangled. There was evidence of rape, but they were sex workers.’

‘Yeah, I know about those,’ said Erika.

‘Okay, well, there’s more. The phone box we found under Andrea’s bed. Crane requested a trace on the IMEI number written on the box. It matches the IMEI number of Andrea’s old iPhone, the one she reported missing. Crane then got in contact with network providers and gave them the IMEI number. They’ve confirmed that the handset is still active.’

‘I knew it! So Andrea reported the phone missing, but kept it and bought a new SIM card,’ said Erika, triumphantly.

‘Yes. A signal was last traced for that handset near to London Road on the 12th of January,’ said Moss.

‘Someone’s nicked it and they’re using it?’

‘No,’ said Moss, pulling out a large ordinance survey map and starting to unfold it. ‘The signal came from a storm drain running twenty feet below ground. It runs off London Road, beside the train track to Forest Hill Station, and then on towards the next station on the line, Honor Oak Park.’