In June 1987, Hannah, a Cherokee woman, drives through the night from Dallas, Texas, to Tahlequah, Oklahoma, with her two daughters. Five-year-old Steph sits beside baby Kayla, who is covered in shards of glass. Hannah is fleeing their father after a violent incident she will not speak of for decades. She brings them to the heart of the Cherokee Nation, a place she claims through her ancestry, and raises them there.
Eight years later, Steph is consumed by a single ambition: becoming an astronaut. She applies to Phillips Exeter Academy, an elite boarding school, and to Space Camp. When the family cannot afford camp, Hannah and her boyfriend Brett, a Cherokee teacher who serves as a father figure, create a free program called Space-Culture Camp. Steph finds it humiliating. During a field trip, she discovers in her mother's purse an Exeter acceptance letter with a full scholarship whose deadline passed two months earlier. Hannah hid it, insisting that leaving home has destroyed every woman in their family.
Steph stays but excels academically and improves her Cherokee. Brett encourages her love of the stars with a telescope. She falls for Meredith, a girl from Space-Culture Camp, during a school play about the Trail of Tears, but Meredith rejects her. On a family trip to North Carolina, Steph catches Brett in an intimate moment with a woman named Beth but says nothing, afraid of losing her only father figure. Brett's affair eventually becomes public. Steph writes a college essay strategically framing her Cherokee identity and traumatic childhood, and is accepted to Hollis College in Connecticut.
A parallel narrative introduces Della Ericson, born Della Owens, a Cherokee girl raised by Mormon adoptive parents in Provo, Utah. Della was the subject of a nationally publicized custody case under the Indian Child Welfare Act (ICWA), a federal law designed to keep Native children with Native families. Her biological father, Matthew, initially signed away his parental rights, then invoked ICWA to reclaim custody. After litigation reaching the Supreme Court, Della was returned to the Ericsons. Now eighteen, she navigates annual visits with Matthew and plans to explore her Cherokee identity at Hollis.
At Hollis, Steph recognizes Della from news coverage and pulls her into the Native American Student Association, whose members call themselves the nassies. Steph pursues Della, and at a party during freshman year they kiss for the first time. Della, terrified by having broken her faith's law of chastity, flees. Over a summer trip to Poland restoring Jewish cemeteries, Della kisses Steph again. At Auschwitz, standing before a pile of children's shoes, she privately leaves her faith. After the September 11 attacks, Della declares the relationship public. She finds a mentor in Professor Andrews, her animal behavior instructor, declares a biology major, and develops a long-term interest in marine biology.
Fractures emerge. When nassie women's faces are pasted onto a racist campus mural, Steph argues against protest to protect her NASA prospects and tells Della she was raised white, striking her deepest insecurity. Steph's sister Kayla visits Hollis during winter carnival and becomes pregnant after a relationship with Jason Palakiko, a Native Hawaiian student. When the nassies stage a protest, Kayla handcuffs herself to the college president's gate wearing a jingle dress, a traditional garment used in Indigenous dance, and goes into labor. The photograph is published nationally. Della, who witnessed the birth of Kayla's daughter Felicia, breaks up with Steph by email, wanting children someday with someone she can trust.
On February 1, 2003, the space shuttle
Columbia breaks apart during reentry. Della finds Steph weeping in the basement and holds her through the night; they reconcile. But the disaster crystallizes Steph's fear that she cannot be both an astronaut willing to die and a partner who stays. Della, whose parents stopped speaking to her for over two years after she came out, has secretly declined every PhD program that accepted her to follow Steph to a lab assistantship in Russia. When Kayla exposes these secret acceptances at a family dinner before graduation, Steph silently moves Della's belongings out of their shared room and ends the relationship without explanation.
Steph spends the next decade in professional isolation: a Fulbright in Russia, dual PhDs at UC Berkeley, and fellowships in Japan and Italy. A serious relationship with a physicist collapses when Steph refuses to compromise. She falls into a severe depression until Kayla flies cross-country to care for her. In May 2015, NASA selects Steph as an astronaut candidate.
Her first assignment is a year-long Mars habitat simulation on Mauna Loa in Hawai'i. Kayla establishes a protest camp nearby opposing NASA's presence on Indigenous land. Steph secretly visits the camp, violating protocol, and begins a brief relationship with Nadia, a fellow astronaut candidate and engineer, before fear of exposure leads her to pull away. When mission commander Allison warns that Steph's unauthorized visits disqualify her from a future space mission, Steph trades intelligence about the protest to mission control, triggering a police response. Through the porthole, she watches water hoses blast the protesters, her sister on the front line and her niece Felicia crawling forward on her knees.
The mission is canceled. Kayla texts that their father died recently of heart disease, not in the childhood car crash their mother described. He survived, remarried, and had four children. Steph does not reply. During a subsequent underwater mission off the Florida Keys, a shark attacks Steph and Nadia in a storm evacuation. Steph stabs the shark, tourniquets Nadia's shoulder, and holds on until rescue arrives.
Steph returns to Oklahoma on crutches. Hannah finally reveals the truth: Their father drove the car off a cliff deliberately. Hannah threw herself into the back seat to shield the children, then ran through the woods, knowing that if she waited for the police she would never leave. At the archives, the family discovers letters from an ancestor detailing the family's reliance on enslaved people, a history Hannah chose to suppress.
Steph reconnects with Della over coffee in Tahlequah, their first meeting in 12 years. Della, now a marine biology professor, has co-adopted a baby with Sam Sherman, a college friend, and rebuilt relationships with all three of her parents. She tells Steph about her life with ease, no longer needing to impress her.
That same day, Hannah suffers a fatal heart attack. The sisters sit together as their mother is taken off life support. Afterward, Brett reveals that the telescope he gave Steph was actually Hannah's idea; she bought it to encourage Steph's love of space. Steph confesses to Kayla that she sabotaged the Hawai'i protest. Kayla forgives her but insists Steph is not as powerful as she thinks.
Both Steph and Nadia receive space mission assignments. Steph and Kayla tour Cherokee schools in North Carolina and Oklahoma, sharing science with children and reconnecting with their homeland. In a final chapter set 10 years later, Steph has married Nadia and made three trips to the International Space Station before being assigned to a lunar mission. On her first night aboard the station years earlier, she stayed awake in the cupola, the station's windowed observation module, watching Earth pass below every 90 minutes. She waited for the coordinates over Oklahoma and searched among a hundred thousand lights for one. Kayla had promised to leave it on.