What does it mean to build a new world from the wreckage of a broken one? This question lies at the heart of Jennifer Mills’ mesmerising fifth novel, Salvage – but it’s one that her gruff, defensive protagonist Jude would rather avoid. For most of the novel, Jude has her head down and is hard at work, cooking, fixing engines, caring for other people. She’s a survivor whose adaptative mechanisms involve leaving everything and everyone behind: “Things will be simpler when she’s on her own. Belonging nowhere, carrying nothing.”

We meet Jude in the village of Northport in the Freelands, on the precipice of a dangerous journey, a narrative moment that both anticipates resolution, and disorients the reader. Mills doesn’t rush to explain how Jude got to Northport or where she’s going; the plot is revealed slowly through the novel’s intricate design. Although Jude tries to convince her friends to stay away, to her immense vexation they won’t let her play the role of the lonely hero – and Mills, anyway, has no truck with narrative models organised around a single exceptional protagonist.

Jude is on a salvage mission, of sorts, but the reader’s questions about what she is saving and why are not answered immediately. Mills devotes her energies instead to building the near-future world of the novel. The contours of the lands traversed by Jude are recognisable to readers in 2025. They are shaped by war and climate crisis, by inequality, by the chaos of extractive capitalism. Here the rich live in locked compounds and pods, the poor labour out of sight. Plants still grow but the seasons are “haywire”.

The Freelanders live in a post-national deregulated zone between “nervous powers” in the postwar era. Together they are building a community according to the principles of distributed democracy, patching up roads that were bombed, reinhabiting abandoned villages; wresting, as Ursula Le Guin, one of Mills’ most important influences, might put it, wild oats from their husks. Both writers are preoccupied with how people form viable communities and Mills’ pays as much attention to the labour of care and repair as she does more traditional novelistic magnets like conflict and resolution.

If you can help, help, the Freelanders remind each other. They welcome refugees, share resources and repurpose the flotsam that washes up on villages dotted along their shores. It’s hard work, building this new world, and although she never hesitates to volunteer for manual labour, Jude tires of the affective slog of community; the tedium of committee meetings and consensus-based decision-making.

To salvage is to be resourceful and by sharing what they salvage, the Freelanders are able to take care of each other and survive. In Jude’s difficult course from fierce independence to apprehensive acceptance of the radical interdependence required to create a better world, Mills provides her reader with a timely model of resistance to despair and passivity.

When a piece of space junk washes up on the shores of Northport, Jude must reckon with all that she has left behind. The rest of the community is almost as quick as Jude to identify it as a life-support pod from the Endeavour Station, a much-publicised spacecraft that served as a refuge for the megawealthy from conflict on Earth. All on board were presumed dead but, by some miracle, the pod contains a skeletal survivor, barely holding on to life. Jude knows at once that this is her adoptive sister, Celeste.

The principal narrative arc of Salvage – Jude’s quest, if we must – concerns this frail body: whether Jude will reveal her connection to Celeste; whether the sisters will have a chance to reconcile. In flashbacks we learn about Jude’s many lives before her arrival in the Freelands: orphaned in infancy, adopted by a wealthy mining family, raised by Celeste and a dwindling domestic staff in a lonely compound. She runs away as a teenager, keeps running and taking on new names – only to realise that “she has spent most of her life in flight, and outrun nothing”.

A third narrative thread brings the reader into Celeste’s dreamy, desperate consciousness as she wakes and falls back into torpor in space. The reader recognises before Jude does that the sisters are conjoined by their conviction that to survive this violent, unpredictable world requires isolation and hard protective shells. Even so, it is a vision of her lost sister that keeps Celeste alive as she floats away from the world.

The three narratives converge at the climax of the novel, which is surprising and generous in its optimism. The resolution of the plot realises Mills’ larger thematic ambitions and demonstrates her technical accomplishment. It’s a beautifully structured novel, complex but never messy, and speaks in urgent tones to our contemporary moment.

Around Jude and her kin, Mills has crafted a novel that amounts to an argument for centring care and community in our strategies for survival. “It was difficult,” Jude observes in an interaction with a Freelander early on, “to unlearn habits of scarcity and competition and possession.” And yet as Salvage insists, with grace and conviction, we must.

• Salvage by Jennifer Mills is out through Pan Macmillan Australia ($34.99)