What happens to your quiet suburban life when it comes to light that your brother is a terrorist? That question painstakingly unravels throughout Stephanie Kegan’s riveting new novel, Golden State, as it follows Natalie Askedahl, the level-headed narrator who suddenly suspects her estranged brother Bobby of being a serial bomber in the likes of Ted Kaczynski. Although the real life story of the Unabomber—who was also identified and turned in by a sibling—is an undeniable influence on this high-stake work of fiction, the idea for Golden State first came from Kegan’s interests in family dynamics, the Billy Carters and Roger Clintons of the world, how siblings can so radically diverge from the womb.

Kegan began by carving out the character of Natalie, a happily married mother of two, a dedicated teacher who grew up in northern California in the ‘60s in a prominent political family. “She’s an observer, busy watching other people,” Kegan explains, “and then what would it be like to have her interest in other people switched around, and suddenly they’re looking at her?” Natalie’s turning point happens when her daughter comes dangerously close to a tragic bombing on the Stanford campus. As new details of the bomber’s manifesto emerge, Natalie is eerily reminded of letters from her brother ranting about technology and the environment, and she soon ties Bobby to a string of other attacks, reluctantly confessing her suspicions to the F.B.I.

For most of Golden State, Natalie resides in a post-traumatic state processing the horror of her new reality as an improbable star in a national news story. Her mother and sister are furious that she could think Bobby was capable of such crimes, and her husband and daughters are desperately struggling for a semblance of normalcy. With a poignantly intimate first person, Natalie moves between the nightmares of the present and memories of the past, obsessively combing her childhood for signs of where things went wrong.

“Bobby once told me that when he was working trying to solve a math problem, he could not stop thinking about it. He analyzed it day and night, took it apart in his head, and started over. I was different. I could lose myself in the everyday. I could push things out of my mind,” Kegan writes. But as Natalie fondly recalls sweet moments shared withBobby, red flags also wave back from the abyss. “I came from a long line of dreamers, of storytellers, and the most dangerous stories we told were about ourselves.”

“The core of this story is denial of mental illness in this family,” says Kegan, who immersed herself in psychological studies to better understand Bobby’s character. “He has to be terrible, and yet we have tohave some sympathy for him. He has to be crazy without seeming crazy.… Like many extremists, it’s not the ideas as much, it’s the conclusion that he comes to.”

Kegan also did a lot of research into California history because she knew she wanted this politically charged family bound to the history of their home state. Many of Bobby’s radical beliefs stem from his parents’ political activism and his longing for a nascent California before globalization changed everything. As a native Californian and graduate of UC-Berkeley, Kegan already knew a lot about life on the left coast. When her father was a teenager he hopped a freight train from North Dakota to California one summer when he couldn’t find work; she grew up in Long Beach with this myth of finding paradise.

A beautiful façade of Bay Area imagery permeates Golden State, delivering a stark contrast to the Askedahls’ doom: “The weather gauge outside my mother’s window registered a warm seventy-four as the girls and I talked of Christmas,” Kegan writes. Natalie continues trying to be a good mother even when she faces the anguish of testifying in her brother’s trial. Balancing Natalie’s delicate psychological state was one of the most difficult parts in the writing process for the author, who took a long break after writing her previous novel, a genuine horror story. 

“When I got into Natalie’s head it was very painful to think about what would happen if I lost everything. What would happen if it was my daughter? Or what would it have been like if it was my brother?” asks Kegan. Her difficult answer to these dark questions is what provides Golden State with a harrowing immediacy. “We all think it can’t happen to us, and it can,” she says.

Bridgette Bates is a writer and editor in Los Angeles. A recipient of a Fulbright and a Boston Review “Discovery” Prize, her first book of poetry, What Is Not Missing Is Light, was released last fall.