I’m impatient for them to leave. We need our house to go under contract as soon as possible to put us in the best negotiating position when we make an offer on the Glass House, and this couple are just tyre-kickers: they haven’t sold their own place, and I can’t afford to get stuck in an unreliable housing chain.

‘I’m afraid I have another viewing in fifteen minutes,’ I lie, heading towards the hallway.

‘We want it,’ Harper says instantly.

Her husband throws her a startled look. ‘Harps—’

‘Come on, Kyle. You know it’s perfect. It’s just what we’ve been looking for. It’s our forever home.’ She turns to me. ‘We’ll offer you full asking right now if you take it off the market.’

The agent’s eyes gleam as she calculates her commission. Harper’s offering nearly double the money we put into the house. Tom would kill me if he knew I was even hesitating.

I’m seriously tempted. We’ve had numerous viewings in the three days since we put it up for sale, but we’re overpriced: no one has come back for a second look.

But I know what it’s like when you find the one.

They say it takes just ten seconds when viewing a new house to see yourself living there. I recognise the property lust in Harper’s eyes.

‘It wouldn’t really be fair to my other interested parties,’ I demur.

‘Whatever offers you’ve already had, we’ll beat them,’ she says.

‘I really can’t—’

‘Fifty thousand over asking.’

Her husband grabs her arm. ‘Harper!’

‘Kyle, we’ve looked at, like, forty-seven houses,’ she says impatiently. ‘Do you want to trail round another forty-seven? And this one’s so much nicer and more homey than that other glass one we just saw. I want this one.’

‘We can’t afford it!’

‘We can if we get that new SugarPop deal,’ she says. ‘We’ll get some great storylines out of moving here. You know we will.’

I can’t decide if Harper Conway is exceptionally smart or a complete idiot. No one goes into a negotiation tipping their hand like this. Either she’s caught up in bidding fever, or she’s playing a clever game: an offer like this certainly cuts through the noise. Either way, it’s a win for me.

‘If you can provide a ten percent non-refundable deposit now rather than wait until we exchange,’ I say, ‘I’ll give you forty-eight hours to prove your house is under contract and that you’ve got the financing to complete.’

Kyle looks shocked. ‘Non-refundable? Harper, we can’t—’

‘It’s a deal,’ Harper says.

SETtalks | psychologies series

Science ♦ Entertainment ♦ Technology

Inside the mind of a psychopath | Original Air Date 9 July

The transcript below has been lightly edited for length and clarity.