‘The app learns each user’s preferences,’ McLean says. ‘But it turns out everybody wants basically the same thing. Someone thin but not too thin, young but not too young, and rich.’ He doesn’t add but not too rich. ‘Users can pretend to be less shallow than that, but the data tells a different story.’

I’m thin, at least. ‘Were Daniel and his old roommate romantically involved?’ I ask.

‘I don’t think so. Danny didn’t talk about her much. And I don’t think he’d ever had a serious girlfriend.’

‘He was dating, though, right?’ Thistle says. ‘With your app?’

‘Well, trying to,’ McLean says. ‘I recommended it to him, helped him take a good headshot. But he mostly didn’t get very far. Women would click wink on his profile, but when they met him in person, it would never go any further. He’d buy them dinner or a drink, and then they’d part ways.’

‘Did that make him angry?’ Thistle asks.

‘It made me kind of angry,’ McLean says. ‘Daniel is a sweet guy. It seemed unfair to reject him just because he was carrying a few extra pounds.’

‘Yeah, that’s harsh,’ Thistle says.

She doesn’t let the sarcasm slip into her voice, but I can hear it anyway. A fat woman is judged much more severely than a fat man. And I heard somewhere that white people get many more clicks—or swipes, or whatever—than people of colour. I wonder if Thistle has been dating since I last worked with her. I wonder if she’s tried an app.

‘But did Daniel take it personally?’ Thistle asks.

‘He was actually pretty upbeat about the whole thing. I mean, he’d seem disappointed when he came home, but the next day he’d just try again. Plenty more fish in the sea, he’d say. As though that was a good thing.’

‘It’s not?’ I ask.

‘No—that’s the whole problem. Why would a woman date a guy who looked like Danny when her phone tells her there are millions of more handsome guys within range?’ He shakes his head. ‘Too many fish. Great for nTangle, but bad for Danny. That’s why I was so relieved when he didn’t come home that night.’

I’m interested now. ‘You last saw him when?’

‘December 2. He’d met someone—I mean, a woman had sent him a wink—and he was going out on a date with her.’

‘Where were they going?’

‘He didn’t say. In fact, I think he didn’t know. She came to pick him up.’

‘From your place?’

‘Yeah. We tell users not to give out their home addresses, but he was pretty desperate. He said he didn’t give her the apartment number, just the building number. He thought that would be safe enough.’

‘So you didn’t see her.’

McLean hesitates. ‘Not exactly.’