She’s a beautiful woman, too. Her bold red lipstick and immaculate blonde finger waves make Stacey think of Hollywood film stars from the Forties, an effect enhanced by a form-fitting grey dress and chic two-tone leather Spectator heels. Stacey has never met a woman who exudes such old-school glamour. Ordinarily, she’d be jealous, but Millie’s beauty is oddly unthreatening. Stacey feels like an art student introduced to Van Gogh: there’s no room for any emotion but awe.

She’s pretty herself, in a girl-next-door kind of way. She looks her age, thirty-eight, but attractively so. Chocolate Duchess-of-Cambridge curls, good skin, athletic. Viewers love her. They can relate to her: her prettiness is aspirational and they tell themselves it’s within their reach given the right styling and make-up and money. But Millie Downton’s classic beauty is in a different league.

‘Have you been here before, Mrs Downton?’ Stacey asks. ‘When the previous owners lived here?’

‘In a way,’ the woman says.

She turns from the window. Tiny diamonds catch the sunshine at her ears, and scatter prisms of light across the room.

‘Mrs Porter, your asking price is higher than it’s worth, objectively speaking, given its size and location, but we want this house, so we’re willing to pay it,’ Millie says. ‘If you sell to us, it’ll be a quick, straightforward sale. Or you could hold out for a better offer, and deal with an endless parade of groupies who come to see you, rather than the house.’

It’s the first indication she’s given that she knows who Stacey is.

Stacey likes her relative fame. Presenting a national mid-morning TV show four days a week means she gets reservations in restaurants that are booked up three months in advance, and sponsorship deals with brands like Marks & Spencer who pay her to wear their clothes.

But it also means she hasn’t eaten a meal out with friends without being interrupted by someone wanting to take a selfie with her in ten years. In fact, she doesn’t really have friends: at least, not civilians. The women she meets outside of work – at her HIIT class, on the board of the PTA – pretend her fame is irrelevant, but of course it colours every aspect of the relationship. They’re either star-struck fans, or beneath their veneer of amity they’re envious and resentful.

Stacey can’t post anything on social media without running it past her PR: it doesn’t take much to get cancelled these days. Every time she steps out of the house, she has to look camera-ready for the ‘candid’ pap shots that keep her in the public eye: it takes a lot of effort to make it appear as if she’s made no effort at all.

Her celebrity also means her husband, Felix, lives in her shadow, a position even the most enlightened man would struggle to enjoy.