Brad Gooch opens “Flannery,” his biography of Flannery O’Connor, with a lost moment: an account of how when O’Connor was 5, the Pathe newsreel company sent a cameraman to her home in Savannah, Ga., to film a chicken she had trained to walk backward. Most telling is that even at this age, she was elusive, standing just outside our grasp.

“O’Connor’s screen debut,” Gooch writes, “exists in all its fragility in a Pathe film archive. … For all of four seconds, O’Connor, a self-possessed little girl, is glimpsed in glaring afternoon light, a wisp of curls peeking from beneath her cap, calmly coping with three chickens fluttering in her face.” Here we have a stunning metaphor for not only her writing but also her existence: brief, glancing, almost impossible to pin down.

“Flannery” is just the second full biography of O’Connor. The other is Jean W. Cash’s “Flannery O’Connor: A Life.” It’s not that plenty hasn’t been written about her; she has, Gooch tells us, “become a one-woman academic industry,” subject of countless dissertations and critical studies.

Yet 45 years after her death at 39 from lupus, O’Connor resists biographical treatment, because other than her writing, not much happened in her life. An only child, born and raised in Georgia, she left to attend the Iowa Writers’ Workshop in the late 1940s before illness forced her to return home.

For much of her adult life, she lived on a family farm in Milledgeville with her mother, going to church and writing every morning and then receiving visitors and caring for her birds.

“As for biographies,” she once noted, in a line Gooch uses as an epigraph, “there won’t be any biographies of me because, for only one reason, lives spent between the house and the chicken yard do not make exciting copy.”

That’s a typically cutting observation — acute, self-deprecating, laced with irony — but it also suggests the difficulty for a biographer in coming to terms with O’Connor as a figure independent from her work.

Gooch draws on interviews and the author’s correspondence to reveal O’Connor’s early life as a willful girl, overprotected and precocious.

This didn’t change as she got older. “When I was twelve I made up my mind absolutely that I would not get any older,” she wrote in 1956 to her friend Betty Hester. “I don’t remember how I meant to stop it. There was something a bout ‘teen’ attached to anything that was repulsive to me.”

Gooch is brilliant on O’Connor’s fiction, passionate and smart, able to contextualize both the individual pieces and the scope of the career. He astutely notes that O’Connor was not really a novelist. She was, rather, perhaps the greatest 20th-century American practitioner of the short story, a writer with an acute moral vision who understood that faith and salvation do not necessarily go hand in hand.