The sentence that spurred Mira Jacob’s first novel never made it into the final manuscript. “ ‘Don’t encourage him,’ my mother said, as though I were capable of parting the barbed wire to lunacy while he crawled through,’ ” she recites. “It all began with the question of what does it do to a family when your sympathy is for the least rational person?”

That inquiry into insanity begat a dazzling debut. The Sleepwalker’s Guide to Dancing is the bighearted saga of a modern Indian-American family that spans 1970s Salem, India, to 1990s Albuquerque, New Mexico. Late in life, talented brain surgeon Thomas Eapen begins talking to people who aren’t there. Wife Kamala urges daughter Amina, a photographer in Seattle, to report home immediately but not to worry about this alarming development.

Jacob writes:

“He’s fine,” Kamala said. “It’s not like that. You’re not listening.”

“I am listening! You just told me he’s delusional, and I’m asking—”

“I DID NOT SAY HE IS DELUSIONAL. I SAID HE WAS TALKING TO HIS MOTHER.”

“Who is dead,” Amina said gently.

“Obvious.”

Jacob was born and raised in New Mexico. “We had the kind of family I describe in the book, the not-blood-related relations, with two other families that were in our position, meaning they were also East Indian and nobody knew what East Indian was,” she says. “They all thought we were Hopi or Apache or Mexican.” She now lives in Brooklyn, where she co-founded Pete’s Reading Series, a popular assembly uniting premier authors with audiences.

It seems she’s always been crazy for fiction. “It’s just this insane thing: a pact between a writer and a reader to live in an imaginary world together. I love that, the whole notion. The fact that you can have a new world floating around you just by opening a book will never cease to amaze me,” says Jacob, who acknowledges that the act of writing itself—pounding away at the keys night after night—represents a major leap of faith that can, at times, feel like a subtle form of insanity.

It took a decade’s worth of diligent work, through jobs, moves, marriage and motherhood, to complete The Sleepwalker’s Guide. “The fact that I took 10 years: You don’t hear that story too often,” she acknowledges. “No one ever celebrates that story. It’s not sexy. But those things that you’re doing in your room alone on weekends when you could be out being social or at least not worrying if you’re actually a writer, those things actually can amount to something. You’re not the next wunderkind, you’re just yourself. It takes a while, and that’s OK. 

During that evolutionary time, The Sleepwalker’s Guide took a shocking turn: During her father’s three-year battle with renal cancer, Jacob all but ceased writing. After his death, she began rewriting all the scenes in the book—with the father as her father. She shared her concern over this development with her husband, documentary filmmaker Jed Rothstein: “I think I’m losing it; I’m losing the book. I keep writing but the father keeps turning into my dad, and I can’t stop, and I know it’s the wrong thing to do. I think it’s against the rules of fiction,” she told him. “Whose rules are these? It’s your book. Are the scenes coming out well?” he asked her. She says she told her husband that she thought the scenes with her father were working well but that “it’s not his life…it didn’t happen to him.”

“Sounds good to me,” he responded.

“It was a sweet, great moment, a breakthrough,” Jacob admits. “So I just did it. For the next three years, every time I wrote a scene that had Thomas in it, I knew I was writing my dad. 

The relationship between Thomas and Amina took on a depth and breadth that breathed new life into the narrative. While Thomas has a confirmed real-world counterpart, don’t mistake Amina for her creator. “I’m more of a shout-y bossy type,” Jacob jokes. “Oh yeah—no, it’s true—it’s terrible. I’m an extrovert, not a hanger back, so with Amina it was about having a lot of patience with that character, waiting for her to reveal herself. It was an exercise for me, having faith that she would move through this life in a certain way that was worth the story happening around her.”

Life, as it happens to Amina, is often tragic. Among the multiple earthshaking events in her life is the teenage death of her older brother Akhil. “Like many people whose lives had formed around a particularly painful incident, [Amina] had grown used to providing ellipses around the event of her brother’s death to keep conversations comfortable,” Jacob writes. “At some point, the subconscious logic of this had spread to the rest of her life so that she rarely talked about things she had been deeply affected by. It wasn’t hard to do.”

Colorful, boisterous extended family and friends further enable her push to the periphery. “Amina was the counterpoint to a lot of difficult, strong personalities in the book, and she was so haunted at the beginning—she’d seen so many things that she’d been thinned out by life,” Jacob says. “Yet she had this brand of magic, her outlook and way of seeing things, that was really fun to develop. I loved what was going on with her internally, just watching her grow, watching her get layers, watching her understand things and be able to put it together.”

A lot can happen over the span of 500 pages, and Amina’s evolutionis absolutely enthralling. In that regard, Jacob handily meets her literary goal. “How fully and deeply are you going to get pulled into this world, how strong are you going to feel that hand urging you forward?” Jacob found herself asking her future readers while writing The Sleepwalker’s Guide. “I wanted to take readers’ hands and say, ‘You can trust me. We can do this.’ ”

Megan Labrise is a freelance writer and columnist based in New York.