Like Emma Donoghue's "Room," Liz Nugent's riveting new novel is narrated by someone who spends their first five years in a locked room, the child of a captive woman and a kidnapper.

But in "Strange Sally Diamond," that child is now a 42-year-old woman who has no memory of being imprisoned. Although the violence in the room is only referred to, not depicted, readers will quickly discern that the trauma lives in her bones, her behavior and possibly — as the novel questions — her DNA.

Sally's mother, Denise, was 11 years old when she was kidnapped by a pedophile named Conor Geary, who chained her to the wall of a soundproof room near Dublin. There, she gave birth first to a boy, whom Geary took away, and later to Sally.

Geary fled when Denise was discovered, and Denise died soon after. At age 7, Sally was adopted by Tom, a psychiatrist who encouraged her reclusive tendencies, and she grows up isolated and socially inept. She takes people at face value and, when Tom dies, obediently carries out his joking instructions — stuffing him into their garbage incinerator and setting him ablaze. ("It was a simple misunderstanding," she tells police.)

Sally's directness provides much of the book's dark humor — when asked if she would like to attend church, she tells the vicar, "No, it's very boring." Her story is interspersed with chapters from Peter, the brother she never knew, as he recounts his experience in the locked room and beyond. As Sally's voice grows more confident, Peter's grows more ominous.

Things turn dark when Sally receives a package containing a teddy bear. She has no memory of the bear, which dates to her time in captivity, yet it provokes powerful feelings. "Why was I so immediately warmed by his presence?" she wonders. "I was overrun by emotions I couldn't understand."

This is an intense book, a page-turner, although the U.S. edition has a slightly modified ending that gives American readers a glimmer of light that Irish readers weren't afforded.

Read on one level, "Strange Sally Diamond" is a riveting mystery, with puzzles piling up. Where is Geary? Who sent the bear and why? Who is Mark, who arrives in the village and seems obsessed with Sally?

But read on another level, it's a psychological thriller about legacy, posing the eternal question of nature vs nurture. Are we doomed to be like our parents? Can we move past our childhoods? "I am not my dad," Peter says repeatedly. And yet.

Love here often takes the twisted form of confinement — not just Geary's cell, or Tom's isolation. Even Sally, late in the book as she seems to be sliding back into her strange ways, says, "I finally had someone who was mine. I loved him, I wanted to … keep him to myself."

As the saying goes, the apple doesn't fall far from the tree. But what if the tree is the thing that is rotten to the core? Can the apple still thrive? Nugent's spectacular novel gives us both despair and hope.

Laurie Hertzel is the former books editor for the Star Tribune. She is at lauriehertzel@gmail.com

Strange Sally Diamond

By: Liz Nugent.

Publisher: Scout Press, 320 pages, $27.99.