For some reason, I have never managed to see David Harrower's Knives in Hens before – just known that it was the play that made his name in 1995, and began an always bold and fascinating career.

I emerged from Yaël Farber's portentous revival impressed but also worn down. This story of a young woman's liberation through the power of language and knowledge seems so heavy in metaphor and meaning that it is almost stifling.

It is set in a pre-industrial village, where life is hard and everyone has their set roles, of heavy labour and arduous obedience to rural tradition. Soutra Gilmour's set is like a Joseph Beuys installation – all brown earth, dark water, heavy felts, dominated by a huge oppressive stone which is both a plot device, a symbol, and an actual millstone which turns the villagers' hard-grown grain into flour.

The action opens with a chicken being plucked, and the naked bottom of Pony William (Christian Cooke) making quick, violent love to his wife (Judith Roddy). She is never named aloud in the play. This is important because this in part is a story about naming, about the way finding words to describe things gives them power. The woman's journey of discovery begins when William compares her to a field: he uses a metaphor which makes her feel she doesn't know enough.

It continues in her encounter with the miller, Gilbert Horn – an outsider said to have killed his wife and child, but also an educated man who reads and writes. The moment he hands her a pen to write her name, and later to describe her thoughts, her whole world changes.

The story, as it unfolds, is compelling. But even at 90 minutes, Farber's darkly emotional direction – with its insistent music from Isobel Waller-Bridge and a soundscape by Christopher Shutt – makes it feel ponderous and slow. It looks glorious, though, with Imogen Knight's movement and Tim Lutkin's lighting creating tableau after tableau that you want to stop and frame like a painting.

The scene where Roddy imagines being in the miller's bed, whirling and writhing in a cloud of flour, is evocative. The moment where William talks to Gilbert about the way his life as the village ploughman stops his imagining other worlds is quietly surprising.

The performances are also suitably intense. Roddy is mesmeric as the woman, her square-browed face registering each new sensation and thought in ravishing detail. I loved the passages where she walks, describing the world she sees, her vocabulary increasing as she "pushes names into what is there" growing in confidence and self-awareness as she does so.

Cooke and Matt Ryan offer rival versions of manhood; both strong and silent, but the husband is hardy handsome, practical and prone to keeping his woman in check, while the miller, all his sadness lying on his shrunken shoulders, inhabits a wider universe. It is an atmospheric, powerful piece; I wish I had enjoyed it as much as I admired it.

Knives in Hens runs at the Donmar Warehouse until 7 October.