All is not well in Belleville. The place might sound like a slice of suburban America with an ersatz French name, but, in Amy Herzog's 2013 play, is almost the exact opposite – an apartment in the centre of Paris occupied by middle-class America.
But then, that's precisely her point. Belleville is an exacting look at American millennials that argues this generation are the complete inverse of their 1950s forebears with their appliances and apple-pie lives. If that looks like progress, the effects – far from female emancipation and equality – are emasculation and emotional disarray.
Grantchester star James Norton and Imogen Poots play newlywed expats Zack and Abby, come to Paris from New Jersey either because he got a good job here or because she always dreamed of it. Each, in other words, is here for the other. She's 28, he's slightly older, but they already seem so sorted.
Their flat, designed by Tom Scutt, is small but artfully done, filled with furnishings from all over the world. Their pot plants are healthy, and their wedding photo album's on show. Abby bundles in with armfuls of Christmas shopping to find Zack, home from his high-flying job.
That she walks in on him w*nking, tinny moans emanating from behind their bedroom door, suggests some chink in their marital bliss. Or does it? It's 2017. It's nothing. Everybody w*nks.
From that infinitesimal misgiving, however, Herzog wrings an emotionally enervating psychological thriller. Belleville is a marital drama as menacing and palpitating as any bunny-boiler. She ratchets the tension from homely to horror with real integrity and restraint. At times, it teeters on a (kitchen) knife edge.
At first, she seems to knock the pair as unworldly, spoilt kids. Abby, in particular, is in her parents' shadow. They holidayed here early on in their relationship and, after the death of her mum last year, she's hanging on phone calls from her father. Zack, meanwhile, smokes dope with his landlord Alioune (Malachi Kirby) – a 25-year old second-gen Senegalese immigrant with two kids and a property portfolio to run. He's late on rent, but still splashing out. The fairy lights and dreamcatchers on Scutt's set give them away as twentysomething adolescents.
Yet Herzog's not entirely damning. Throughout, she shows that gender relations have flipped – but not entirely. Zack might be the caring, contemporary metrosexual man, ready to massage a stubbed toe or mop up pools of puke, but he's still expected to be the big, bad breadwinner. Abby, for her part, has no housekeeping duties but she's still a kept woman, far from independent. His care sometimes feels horribly controlling, while her leisurely lifestyle masks real mental health issues. As Abby tries to get off anti-depressants, Zack's increasingly reliant on the self-medication of weed.
Norton is perfectly cast as Zack: the picture of outward masculinity and yet strangely wet behind the ears as well. Poots too seems entirely together until she's hobbling around drunk and taking a knife to a blackened toenail. At its simplest, this is a portrait of care and the pressures that come with it. Their relationship is full of real, lived details – the tenderness and shorthand that betrays their history - under Michael Longhurst's direction, but, with Natasha Chivers' clever lighting and Ben and Max Ringham's unnerving urban soundscape, he subverts the tricks and tropes of horror with real skill.
Because that's what this is: a millennial mental health horror. Herzog captures it with empathy and eloquence. A couple stuck overseas, trapped in a bad marriage, rejecting their parents' lives yet cracking their security - that's a perfect encapsulation of a generation caught between crises.
Belleville runs at the Donmar Warehouse until 3 February 2018.