In the small rural community of Carralon Ridge, Australia, a coal mine operated by the Lentzer corporation has been steadily consuming the town for years. Properties have been bought out, residents have left, and the once-thriving community has dwindled to a handful of holdouts. Five years before the novel's present day, Sam Crowley, a 21-year-old university student writing his thesis on the impact of mining on rural communities, drove his rental car to a dirt track leading to three abandoned houses on the outskirts of town. His footprints showed he entered and exited each house alone. His car was found locked that evening, his belongings undisturbed inside, and his birthday dinner sat cold on his family's kitchen counter. Sam was never found.
Sam's mother, Ro Crowley, returns to Carralon Ridge each year around the anniversary of his disappearance. A former general practitioner who practiced at the town's now-shuttered medical center, Ro left Carralon after Sam vanished. Her estranged husband, Griff, remained behind, working as a fire safety officer paid by Lentzer to monitor spot fires from spontaneously combusting coal. They never divorced but have lived apart for years, their marriage fractured by grief. Their daughter, Della, a 23-year-old junior accountant in Sydney, has also returned.
The town's decline shocks Ro anew. The pub, the Black Creek Inn, opens only a few nights a month. Former neighbors have abandoned their homes for nothing, unable to find buyers. While visiting the abandoned ivy cottage with Ann-Marie Birstock, a traveling nurse and old friend, Ro learns that Griff's contract with Lentzer has not been renewed, news he had not yet shared with her. Within three months, he will lose his job and the house they once owned, which Lentzer bought and rented back to him.
Ro visits the three houses where Sam's trail went cold. The ivy cottage belonged to Ann-Marie until her ex-husband forced its sale. The sandstone bungalow was home to Bernie Reece, the father of Noel Reece and an elderly former volunteer firefighter pressured into selling after decades of resistance. The weatherboard farmhouse belonged to Warren Hillary, Griff's cousin, whose death eight years earlier still haunts the family. Warren refused to sell to Lentzer, even as the pressure fractured his relationship with his partner, Sylvie, who ran the pub. One night, Warren's body was found at the bottom of the mine's quarry, and the inquest recorded a verdict of misadventure. His death, coming shortly after Ro's father's sudden passing, damaged the entire Crowley family. Sam, then 17, began taking antidepressants, a fact his parents learned only after his disappearance.
Multiple threads converge during Ro's visit. Della confides that she has been pursuing a lead. Months earlier, she encountered a former girlfriend of Darcy Reece, the eldest son of Noel and Heather Reece, who recounted a drunken incident from years ago. Darcy had become furiously defensive about Warren, and his friend Jacob, Ann-Marie's son, blurted out that Darcy should feel guilty because Darcy had done something stupid, and then Warren had killed himself (145). Both Darcy and Jacob refuse to explain.
Meanwhile, Ro and Griff make a discovery at Warren's decaying verandah. Prying up damaged floorboards, they find extensive old bloodstains and a small silver key wedged between the planks. They try every lock they can find throughout the town without success. Griff raises another troubling detail: On the day Warren died, the sausages on his barbecue were burned only on the bottom, as though something interrupted him mid-meal.
Ro confronts Sylvie about a cryptic entry in Sam's research notebook, where he scrawled questions about Warren and Lentzer beside Sylvie's interview. Emotionally raw after her mother's stroke, Sylvie finally tells the truth. She had pressured Warren for years to sell so they could move closer to her ailing mother. On his final night, Warren called and told Sylvie he would sell because he would rather be with her than in the house without her. Sylvie, already furious, told him it was too late. She never told anyone about his decision, ashamed of the argument and wanting to protect his reputation. Sylvie confirms Sam asked about this during his research, implying he had heard Warren planned to sell.
Jacob comes forward and confesses that as bored teenagers, he, Sam, and Darcy carried out escalating pranks on their neighbors, including moving Bernie's car and removing Ann-Marie's bed to a paddock. The pranks eventually focused on Warren: hiding his tools and stealing his father's running medals one at a time. Four medals are later found among Sam's belongings. After Warren's death, the boys stopped, consumed with guilt.
A separate revelation from Warren's brother, Damien Hillary, explains why Sam visited the three houses. During their interview, Damien mentioned that Warren had carved small faces with zigzag "W" mouths all over the properties as a teenager, his own form of youthful vandalism. Sam, carrying guilt about the pranks, drove out to see the carvings, seeking reassurance that Warren would have understood. Ro and Griff confirm that Sam's footprint pattern matches the locations of the carvings. The discovery explains why Sam went to the houses but not what happened afterward.
On the eve of Sam's birthday, Ro discovers that Griff has secretly restored her long-dead vegetable garden, replanting it with hardy native species and threading their wedding arch with climbing jasmine. She goes to him that night, and they reconcile. At the memorial gathering the next day, Darcy makes an unexpected speech urging the community to stop clinging to what Carralon once was.
Afterward, standing where Sam's car was found, Ro experiences a sudden intuition. She thinks of the silver key from Warren's porch and of Bernie's blue front door, salvaged from his bungalow and installed at the entrance to the Last Chance Saloon, a cabin on the Reece property filled with rescued remnants from abandoned homes. She and Griff drive to the saloon. The key slides into the lock of Bernie's old door and turns.
Through flashback, the truth emerges. On Warren's last night, Bernie walked through the open front door and overheard Warren telling Sylvie he would sell. Knowing the sale would trigger the mine's expansion and force him from his own home, Bernie tackled Warren in a surge of desperate rage. Warren struck his head on the outdoor table. Noel, who had been at the front of the house, found his father kneeling on the bloodied porch and, rather than call for help, drove Warren's body to the mine, cut the perimeter fence, and placed him in the quarry.
Three years later, Sam encountered Noel on the road after visiting the three houses. Noel offered him a ride to pick up some maps. At the saloon, Sam mentioned that Bernie had referred to Warren as someone who sold out and asked Noel to correct his father. Noel inadvertently revealed knowledge he should not have possessed about Warren's phone call to Sylvie. Sam sensed the inconsistency. Noel, recognizing that his secret was also his father's, killed Sam and buried him beneath the saloon floorboards in a corner he cordoned off, claiming subsidence.
Bernie tells Ro and Griff: "It was my fault...So I'll tell you" (293). He admits to the confrontation with Warren, and Noel confesses to killing Sam. Bernie claims he never told Noel about Sam but adds: "It doesn't mean I didn't know. Of course I knew" (309). Noel calls the police. Sam's remains are recovered.
One year later, Ro and Griff have moved to a cottage in a country town between Sydney and Carralon. They have planted Sam's sunflower seeds and transplanted their wedding arch into a new garden. The three houses have been demolished. Heather has moved to Sydney with her younger sons, Zach and Kyle. Darcy and Jacob run a small business in Blenheim, financed by Damien. Ro reflects that in his final days, Sam was home and happy, and the novel closes with Ro, Griff, and Della turning toward their new house, carrying everything they need to feel at home.