The opening night of this Complicité production was aborted at the 11th hour last week when its star, Kathryn Hunter, took ill. As the actor Amanda Hadingue walks on to a bare stage, house lights still on, and begins to speak about coughs and Covid, it seems to be leading to another postponement. Complicité fans may recognise this unassuming start as a signature move, however, and know not to be fooled. From the simplicity of a single actor at a mic, this show directed by Simon McBurney grows like its own verdant forest. It becomes an almighty and toweringly innovative adaptation of Nobel laureate Olga Tokarczuk’s murder mystery eco-noir novel, written in wry, profound and glittering prose. With the help of an autocue (entirely excusable given the gargantuan burden of narration), Hadingue plays Janina, a beady-eyed, chronically sick animal lover living in a remote Polish village rocked by a series of inexplicable murders. The dead are all from the hunting club and Janina volubly espouses the theory that woodland animals are getting their revenge. Her friends – Dizzy (Alexander Uzoka), a former student; Boros (Johannes Flaschberger), an entomologist; and Oddball (César Sarachu), a neighbour – are all outsiders and non-conformists. Janina is a fabulous creation, both hero and antihero. She is a thorn in the side of the authorities, shooting off messages to the police and quoting government laws at the council – a Miss Marple, lady of letters and Fargo’s Marge Gunderson in one. Hadingue inhabits her so fully that we feel her grief over the death of her dogs – “my girls” – as an epic tragedy. Though Janina is, on the face of it, an animal rights activist, the core of this drama is about the condition of being human: how we live and age, our burdens, privileges and abuses. Theatrically, this is a masterclass in how to fill a big stage, in part through sound (Christopher Shutt) and lighting (Paule Constable). The set by Rae Smith emerges organically until it seems there are forests behind and constellations above, much of it created through Dick Straker’s astonishing video design. Scenes flare up out of darkness, with no visible setting up or dismantling. Present and past zoom back and forth so smoothly that it looks entirely seamless. The back-screen is used to brilliant effect, Janina’s projected nightmares of her dead mother appearing almost Hitchcockian. Metatheatricality – nothing over-excitable – brings humorous flourishes: “May I borrow your microphone?” says Boros, who proceeds to tell us his backstory. “Will you turn that fucking music off?” shouts Janina as a stage instruction. There are beautiful moments of physical theatre too. A deer is played by actors with raised hands for antlers, and other creatures often come in human form too, which reflects Janine’s view of animals having the same right to life as us. Tokarczuk’s book was accused of inciting eco-terrorism and its 2017 film adaptation, Spoor, charged with being anti-church. It is a critique of religious dogma in so far as regarding the elevated status of human life above animal as hubristic. Janina holds life sacred in all its forms. Crime story melds into environmental clarion call, fatalism sits alongside hope, and cosmic fatefulness against finding freedom, all of it masterfully interwoven and magnificent to the end. At the Barbican, London, until 1 April and then touring Europe until 17 June