“Sharp Objects” is about a murder case, but Camille Preaker (Amy Adams) is the real mystery.

Camille, a wayward, self-destructive newspaper reporter in St. Louis, gets an assignment that she’s particularly close to: the murder of one young girl and the disappearance of another in Wind Gap, the small town Camille fled years ago. Her editor (Miguel Sandoval) hopes she’ll find a sense of purpose as much as a prizewinning story.

She arrives back home carrying a bag of candy bars and vodka bottles, as well as a childhood’s worth of bad memories. Images of the past — a sister who died young, her distant mother, the town’s foreboding woods — flicker up in the middle of scenes, as if Camille’s head can’t contain them.

“Sharp Objects,” a mesmerizing eight-episode series beginning Sunday on HBO, is not the gothic crime thriller you might first suspect — at least not mainly. Instead, the show’s attention is drawn backward to Camille’s injuries, emotional, physical and self-inflicted. (The title alludes to her habit of cutting words into her flesh, leaving her body a dictionary of scars.)

Camille returns to the stately, rambling home of her mother, Adora (Patricia Clarkson), whose greeting is icy enough to chill a julep: “The house is not up to par for visitors.” Their history is being repeated in miniature by Camille’s young half sister, Amma (a captivating Eliza Scanlen), who is demure (like Adora) at home but wild and rebellious (like Camille) with her friends.