Birnam Wood by Eleanor Catton review – the root of all evil

In his great critical work The Sense of an Ending, Frank Kermode wrote about the end-directedness of fiction, the way that novels rehearse and forestall their endings – a process he called peripeteia. One thing he doesn’t discuss in that book is what happens when an ending entirely alters your understanding of the text. There are numerous examples of tricksy plot twists – think Fingersmith or Fight Club – but I’m not sure I’ve read a novel whose ending so brilliantly and brutally changes our perception of what has gone before as Birnam Wood, Eleanor Catton’s follow-up to her Booker-winning The Luminaries.

For nine-tenths of its 400 pages, Birnam Wood comes across as a Kiwi Jonathan Franzen – a smart, satirical novel about the clash between a gardening collective and a scheming tech billionaire. There are numerous Franzen tropes here – countercultural/capitalist discord; the striving for ideological purity; the relentless and vampiric march of big business; environmental crisis. There’s even a rare bird – here it’s an orange-fronted parakeet. Birnam Wood is like a Franzen greatest hits album until its glorious, apocalyptic final pages enlarge and complicate our understanding of its message.

Mira Bunting is one of the principal figures in Birnam Wood, founder of a group of guerrilla gardeners who tend 18 plots of vacant land around Christchurch and dream of self-sufficiency, which they describe as “breaking good”. Mira is 29 but, like many of her friends, appears trapped in an extended adolescence. She lives with Shelley Noakes, her “sensible, predictable, dependable sidekick”. Birnam Wood has grown into a thriving (if still decidedly loss-making) project, whose aims are to grow food and flowers while operating “as much as possible outside a capitalist framework”. Already, though, capitalism has sought to subsume projects like theirs. “Birnam Wood was now a startup, a pop-up, the brainchild of ‘creatives’; it was organic, it was local; it was a bit like Uber; it was a bit like Airbnb.” Mira and Shelley are resistant to this linguistic colonisation of their world, although they also recognise the need to make the project financially viable.

That wish seems suddenly to be granted with the arrival of the charismatic, tracksuited billionaire Robert Lemoine. Lemoine’s company, Autonomo, builds drones and has recently embarked on a joint venture with a New Zealand pest control entrepreneur, Sir Owen Darvish. Lemoine has also bought the Darvish family home in Thorndike, a (fictional) mountain village in the (also fictional) Korowai national park. Lemoine claims that he’s just another “doomsteader” buying up a New Zealand bolthole. Instead, we learn that he has discovered rare earth minerals in the park and has begun mining them, a process that has already unleashed environmental devastation. Lemoine meets Mira as she’s out scouting for potential Birnam Wood planting sites. He offers her land and cash – the dream of “breaking good” seems to have arrived.

Only Tony Gallo seems sceptical of the collective’s sudden good fortune. Tony, a co-founder of Birnam Wood who has been away travelling for several years, is horrified to find that capitalism has taken hold of the gardening project. He makes an impassioned speech at the group’s hui (meet-up) and is shown the door. The rage that energises him here, which he sums up later as anger “at the sheer inexorability of late-capitalist degradation not just of the environment, not just of civic institutions, not just of intellectual and political ideals, but worse, of his own expectations, of what he even felt was possible any more…” is the sustaining rage of the novel. Mira, Shelley and the rest of Birnam Wood (and, by extension, the reader) initially see Tony as a throwback, his views as incompatible with the new spirit of the collective. In fact, the events of the novel seem designed to assert definitively that there can be no accommodation between capitalism and projects that seek to deliver benefits that are communal, cooperative and non-financial.

Related: Eleanor Catton: ‘I felt so much doubt after winning the Booker’

We are living in the age of the B Corp and caring capitalism, of ESG and green investment. Birnam Wood’s message, underlined in blood-red ink by its extraordinary conclusion, is that these attempts to shape a gentler form of capitalism are doomed to failure. Greed is not only not good, it is actively evil and aggressively expansionist. As Birnam Wood’s benevolent beginnings are warped and tainted by their association with big tech, we recognise that only by reclaiming the purity and radicalism of the group’s origins can Mira, Shelley and Tony hope to rescue it. Birnam Wood is a dark and brilliant novel about the violence and tawdriness of late capitalism. Its ending, though, propels it from a merely very good book into a truly great one.

• Birnam Wood by Eleanor Catton is published by Granta (£20). To support the Guardian and Observer order your copy at guardianookshop.com. Delivery charges may apply