An hour later, Kate was just finishing her second glass of Sauvignon Blanc, while Laura was still nursing her lager.

‘I can’t believe some of the stuff people are willing to list on their profiles,’ Laura said as she continued to study the laptop screen.

‘This is the digital age we live in.’

‘I take it you’re not on Facebook then, ma’am?’

Kate fired her a look. ‘Kate.’

Laura blushed slightly as she nervously glanced up. ‘Sorry, it just takes a bit of getting used to.’

‘Where are we with that lot?’

Laura sat back, and stared at the sheets of paper she’d been scribbling notes on. ‘As you said at the start, it’s not easy to narrow down. I’ve managed to access the Pinterest accounts for Steph and Willow, but it doesn’t look like Roxie used it. She did use Twitter occasionally, however, and based on what the three of them pinned and retweeted, it’s safe to say they shared interests in health and fitness. Both Steph and Roxie followed businesses promoting health and vitality drinks, as well as a number of celebrities who regularly tweeted about one diet or another. Of the three, Willow was in the best shape, but we know from the original investigation that she was a member of the gym she worked at, so it’s not difficult to assume she was body-conscious too.’

Kate pulled a face. ‘Doesn’t exactly narrow it down, though, does it? Show me a woman who isn’t body-conscious. What else have you found?’

‘Well, it’s kind of along the same lines, but they all shared swimming as an interest.’

‘Swimming?’

Laura reached for her glass of lager and took a long sip. ‘Yeah. We know from Roxie and Steph’s bank statements that they both paid membership fees to gymnasiums. Roxie’s was for a place in Lower Sydenham, and Steph was registered at Finsbury Leisure Centre in the months before she died.’

‘And Willow worked at Watford Leisure Centre Central, right?’

‘Correct.’

‘Do you think the killer was also a member of these leisure centres?’

It was Laura’s turn to pull a face. ‘It’s weak, isn’t it?’ She snapped a piece of poppadum.

‘Well, it’s an angle the original investigation missed, and something we should follow up on. If we could get hold of a list of their members we could cross-check it with the names extracted from the dating sites.’

‘If you could get your hands on those lists. Do you know anyone on the current enquiry who could pass those along?’

The image of Armitage warning her to keep away flashed before Kate’s eyes. ‘I’ll have to work on that. What else links the three?’

‘None of them owned cars as far as I can tell. They each have Transport for London charges on their bank statements for Oyster card top-ups. I can’t see any direct debits for motor insurance or breakdown cover.’

‘So, swimming and public transport. Maybe if we phoned the leisure centres we could ask if they still have CCTV footage from 2015, and then we might see our perp watching them leave?’

Laura groaned. ‘Please don’t mention security cameras. Think I might go blind if I have to sit and watch random cars driving down the road again.’

‘You should have a word with Underhill and ask him for something else to do.’

‘I know, but I don’t want to rock the boat. I think he’s feeling the pressure of you not being around.’

Kate tilted her head. ‘What do you mean?’

‘You must have noticed it?’

‘What?’

‘Ever since you solved the Watson-Jacobs-Yen triple murder last year, he’s been like a bear with a sore head. While your record has gone from strength to strength, his has been on the slide. With you out of the office, he’s head honcho and he’s desperate to bask in some limelight of his own.’

‘The priority is solving crime and protecting the public.’

‘Oh, I know that, I was just making an observation.’

Kate smiled; it was good to know she wasn’t the only one on the ropes. Laura’s mobile erupted to life. Fishing the device from her pocket, Laura put it to her ear. ‘Trotter… Oh I see, sir. On my way.’

She stood, placing what remained of her lager on the table. ‘Sorry, Kate, I need to go. That was the supe. The body of another woman has been found, it’s in a car beneath some offices in town this time.’ Laura reached for her coat.

Kate stood, flattening her top. ‘Mind if I tag along?’