Helena Pelletier is a young mother living in Michigan's Upper Peninsula, where she sells homemade jams and jellies. She has two daughters, five-year-old Iris and three-year-old Mari, and a husband, Stephen, a nature photographer. Helena struggles with social conventions and timekeeping, remnants of an upbringing she has hidden from everyone. She is the daughter of Jacob Holbrook, a man the media dubbed The Marsh King, who kidnapped a 14-year-old girl and held her captive for more than 14 years in a remote cabin surrounded by impassable marshland. Helena was born during the captivity and spent her first 12 years on that isolated ridge, never seeing anyone besides her parents, never attending school, never knowing electricity or running water. Her mother, who never recovered from the ordeal, has died before the novel opens. When Helena met Stephen at a blueberry festival seven years earlier, she concealed her identity, and the deception grew until she felt she had too much to lose. She married him without revealing that they live on property once belonging to Jacob's parents.
One afternoon, while driving home with Mari, Helena hears a radio alert: Jacob has escaped from the maximum security prison in Marquette, killing two guards during a transfer and fleeing into the Seney National Wildlife Refuge, roughly 30 miles from her house. Helena knows the refuge trail is a decoy. Her father can move through the marsh unseen and would never leave a trail unless he wanted searchers to follow it.
She races home, locks the house for the first time, and monitors the news while hiding her terror from the girls. That evening, two state police officers arrive to question her just as Stephen pulls into the driveway. When the officers address her as Jacob Holbrook's daughter, Stephen is blindsided. After they leave, he confronts Helena, devastated by the scope of her deception. He packs the girls into the car and drives to his parents' house in Green Bay, Wisconsin. Helena refuses to go. She tells Stephen the police need her, but her real reason is that she believes she is the only person capable of tracking her father. Jacob trained her in wilderness survival and tracking from infancy. Capturing him is the only way to prove that nothing matters more to her than her family.
The novel alternates between Helena's present-day pursuit and extended flashbacks she calls "The Cabin," recounting her childhood in the marsh. Her father was patient and knowledgeable, teaching her to track, hunt, and read the natural world with extraordinary skill. On her fifth birthday, he let her choose a knife from his collection and took her to the snare line, where she made her first kill. He dipped his fingers in the rabbit's blood and drew stripes across her cheeks, saying
"Manajiwin," the Ojibwa word for respect.
But Jacob was also violent and controlling. He locked Helena in a dry well as punishment and carved the word "NOW" into her forearm when she refused to help her mother at age 11. He beat her mother regularly, kept her shackled during the early months of captivity, and carved degrading words into her skin. The summer Helena was 11, her mother tried to take the canoe to a nearby ridge, and Jacob dragged her back by the hair and held her head underwater until she went limp. This was the first time Helena understood that her mother was a prisoner.
Helena's understanding of the outside world came from 1950s-era
National Geographic magazines and a book of Robert Frost poems. She created imaginary friends, Cousteau and Calypso, modeled after two children she glimpsed at Tahquamenon Falls during a winter expedition with her father. Seeing a real family playing together made Helena realize she could not stay in the marsh forever. That same winter, she discovered a teen magazine her mother had hidden, whose date revealed the
National Geographics were 50 years old. Everything Helena believed was current was decades out of date.
Soon after, a lost snowmobiler named John Laukkanen stumbled onto their ridge. Helena's mother recognized him as someone from her hometown of Newberry and pulled him inside, desperate to escape. When Jacob returned, he beat John savagely and handcuffed him in the woodshed. Over the following days, John told Helena the truth: Her father had kidnapped her mother as a girl, and people had never stopped searching for her. Guided by Cousteau and Calypso, and inspired by "The Marsh King's Daughter," a Hans Christian Andersen fairy tale her mother once told her about a girl torn between her wild father's nature and her gentle mother's, Helena decided to flee. She killed John with her knife as a mercy, sparing him from further torture, then loaded her barely conscious mother onto John's snowmobile and drove away from the cabin for the first time in her life. Jacob returned and opened fire, wounding her dog Rambo and shooting her mother in the shoulder. With his last bullet, he killed Rambo as the dog charged him. Helena escaped across the frozen marsh and was found on a road by strangers.
In the present-day hunt, Helena sets out at dawn with her three-legged Plott hound, Rambo. She receives a text from Stephen: He is coming home, the girls are safe, and he signs off with "Love S." His forgiveness strengthens her resolve. Along the way, she discovers a sheriff's officer shot in the back in a ravine, with "For H" written in blood on his chest, and later finds another victim in a remote cabin, shot execution-style. Her father slashes her truck tires and takes Rambo, leaving tracks toward her house. Helena takes an alternate route along a logging road her father cannot know about and runs to get ahead of him. From a ridgetop, she spots Jacob wading through a creek, gaunt after 13 years in prison, with Rambo on a leash. She fires a warning shot, but Jacob feigns surrender and shoots her in the shoulder. He handcuffs her and reveals his plan: He wants Helena to drive him and her two daughters to Canada, where they will live as a family. He learned about the girls from a
Traverse magazine article featuring a photograph of Helena's family on the property where Jacob grew up.
Forced to march at gunpoint, Helena throws herself off a steep cliff along the trail, tumbling 100 feet into a creek. She lies motionless until Jacob moves on, then circles through the marsh despite her handcuffs and wounded shoulder to set an ambush near the beaver pond behind her house. Armed only with a broken pine branch, she attacks when Jacob approaches. They grapple in the mud until Rambo appears, having found his way home, and clamps his jaws around Jacob's leg. Helena pins her father with his own Glock. He whispers
"Manajiwin." Helena whispers "I love you, too" and pulls the trigger, killing him.
In a brief epilogue set months later, Helena is recovering from shoulder surgery. She sits with Stephen and the girls at her mother's grave, surrounded by marsh marigolds and irises, the flowers for which she named her daughters. Stephen asks Helena to tell the girls about their grandmother, and Helena tells them about a chocolate birthday cake her mother once baked, leaving out the darker parts. Helena has written everything about her childhood in a hidden journal she calls "The Cabin," dedicated to her daughters. She intends to let them and Stephen read it someday but will never sell the story. It belongs to her family.