‘Yeah, but it’s no big deal. Most people use fake IDs. They’re not dumb enough to put their real identity out there, okay? Kelly wasn’t Kelly online. If you talked to her, she said her name was Corinne, and she was from Maryland. And it’s not like gender-bending is so odd. The fact is, women will talk to other women. They’re on their guard whenever men approach them. So Beccababe can get to know women, which Mort Sanders can’t. I’ve made a lot of great women friends that way.’

‘By lying to them,’ Serena said.

‘I lie about my outer self but not about my inner self.’

Serena rolled her eyes and waited for the noise of a passing train to diminish. ‘Let’s get back to Kelly. Why are you here asking questions about her murder?’

‘I was reading a copy of the Star Tribune, and I saw an article about this murder victim in Duluth being identified. Kelly Hauswirth from Colorado. I saw the pic, and it was her. It was a shock. I felt really bad. So I just wanted to find out more about what happened to her.’

‘You said Kelly had a different identity online,’ Serena reminded him. ‘How did you know who she was? Did she tell you her real name?’

Mort wet his lips with his tongue. ‘No.’

‘So how?’

‘It’s kind of a hobby of mine.’

‘What is?’ Serena asked.

‘I collect people.’

‘Collect them? What does that mean?’

‘You’re going to think it’s weird,’ he said.

‘Oh, we’re way past weird.’

‘Look, I swear, it is totally innocent. I never do anything to them. I told you, it’s just a hobby.’

Mort slid a smartphone out of his pocket and punched a button to pull up his photo stream. He held it so Serena could see the screen, and he used his thumb to flick through a series of photographs. They were all unposed shots of ordinary people in ordinary places. A middle-aged woman in a grocery store. A teenager coming out of school. An older man in a suit getting on a bus. And then – Kelly Hauswirth. Serena recognized her. She saw Kelly jogging on a treadmill at a suburban gym.

‘Where did you get this photo?’ Serena asked.

‘I took it.’

‘How?’