Girls & Boys is not what it may sound like. No, this is not a harmless romance about a boy and a girl, although it begins as one. But as time goes on, our unnamed narrator (Carey Mulligan) delicately unravels her life for us. Boy meets girl, they fall in love, get married, have children – but it silently goes sour, descending quietly into every woman’s, every parents’, every person’s nightmare. I won’t give any of it away, but her story explores gender politics, equality, violence and power, in a disturbing and visceral way. It considers how we view and treat the sexes differently, and what the consequences of this are, Girls & Boys being among the worst imaginable scenarios.

Mulligan, as our unnamed narrator, is incredible. Beginning at joy and ending at pain, she drags us through it all with her. She has excellent comic timing, something I hadn’t necessarily paired her with in my mind, what with her quite sombre back-catalogue (Suffragette, Far From The Madding Crowd, Never Let Me Go). My only niggle is casting her as what is supposed to be a working-class girl who crawls her way up and out of her surroundings “like a rat”. I’m immediately perturbed when I hear she’s removed the plum in her mouth, and is subtly dropping her h’s in the beginning of the piece. It doesn’t suit her and seems foreign and unnatural, but I let it go and it becomes an insignificant detail, and everything else more than makes up for it.

Dennis Kelly’s (The Ritual Slaughter of Gorge Mastromas, Matilda the Musical) writing is a joy, funny and observant, almost lyrical in its delivery by Mulligan. The plot is so layered, that when the truth is unfurled at the end, we aren’t even that surprised – or I wasn’t. When I look back, it all adds up – the signs were always there. Kelly’s delicately dropped clues, while carefully woven in, aren’t that delicate at all. All of a sudden we realise why we have a bad taste in our mouths, and that terrible ‘oh god’ moment comes sweeping over us. How could we have missed it?

Directed by Lyndsey Turner (Posh, Hamlet), together the pair has created a play that is a punch in the gut. Girls & Boys is frankly, terrifying. And hauntingly, we see history repeating itself in the protagonists’ two children, a girl and a boy. The gender based violence inflicted in this piece is a special kind of cruel, one that many women have experienced on some scale, and many more will – unless we do what Girls & Boys is doing, unless we start talking about it.

Girls & Boys is playing at the Royal Court Theatre until 17 March 2018

Photo: Marc Brenner