Claudia Piñeiro’s novel “Elena Knows” comes to the screen as a convuluted and mournful affair, a moody murder mystery whose solution seems too obvious too soon to truly come off.

Gabriela Larralde’s script transforms the compact single-day search for answers about why Elena’s adult daughter was found hanging in the bell tower of the church school where she taught into something more drawn-out, immersing us in the sadness and the building of “the case,” but spoiling any sense of mystery.

When we meet her, Elena (Mercedes Morán) is enfeebled and bitter. Stooped, walking with her eyes always fixed on the ground in and around Buenos Aires, it takes a while for us to figure out what ails her.

She has a pill regimen and a fridge full of prepared meals, all of this maintained by her 40something daughter. And whatever’s going on with her now, “life itself” gives her no pleasure. Daughter Rita (Erica Rivas, quite good) is prone to tears in her presence.

Maybe a visit to the hair salon will cheer her up. A nice dye job. Sure, the conversation with the hairdresser has a disappointed edge, but let’s move past that.

But when nobody comes to pick Elena up at the end of the day, when Rita doesn’t answer her phone, we expect the worst. It comes in the form of a cop at her door late at night, a body to identify in the morgue, and questions.

Rita was mortally afraid of lightning. Would she go out in a storm? Why would she hang herself in the church, where her long-standing crush, Father Juan is priest? What’s up with her husband, the weepy Paolo? Why are her students — one in particular — so disrespectful at the funeral home?

The cops consider the “case closed.” But Elena knows there is more to this, and is determined to get an autopsy and get some answers — harassing people, collecting appointment books and the like, even paying to have a banner demanding answers hung across the street from the parochial school.

Director Anahí Berneri is stingy with the clues here. Elena’s malady isn’t mentioned until midway through the movie. Other wrinkles in the narrative, designed to make us doubt this or that conclusion, are underwhelming if plausible.

Because the flashbacks are the real story.

Morán (of “Norma” and “Neruda”) is a riveting presence, carrying the narrative along its path, creating an unlikable heroine of stern convictions and unbending principles. Elena is one of those women (We never see a husband or hear a word about Rita’s father.) to whom EVERYTHING is a “principle.”

Miranda de la Serna ably plays Young Rita in flashbacks — open-hearted, desperately wanting to have a cat, and shut down every time she brings in a stray. We see young Rita struggling against them, but slowly absorbing her mother’s values.

The problem with “Elena Knows” is how early on we “get” that. It’s not that we “know” as soon as Elena does. We know sooner, too soon for this mystery to remain mysterious.

Rating: TV-MA

Cast: Mercedes Morán, Erica Rivas, Mey Scápola and Miranda de la Serna

Credits: Directed by Anahí Berneri, scripted by Gabriela Larralde, based on a novel by Claudia Piñeiro. A Neflix release.

Running time: 1:39