Diego Luna got his feet wet as a director with the promising 2011 debut, Abel, a slight but disarming tragicomedy that took imaginative shots at Mexican patriarchy and manhood. He followed in 2014 with the larger-scale Cesar Chavez, a pedestrian bio-drama that forfeited any shelf life it might have had when evidence accusing the iconic labor unionist of sexual abuse, grooming and rape surfaced earlier this year, all but obliterating his legacy. Next came 2016’s Mr. Pig, a hog farmer road-trip movie with Danny Glover and Maya Rudolph which I flatly refuse to believe exists.

Sadly, Luna’s inert fourth feature behind the camera, Ashes (Ceniza en la Boca), is unlikely to course-correct that faltering trajectory. Based on a well-regarded novel by Brenda Navarro, it’s a wafty character study so stripped down and elliptical that it lacks the connective tissue to hook us into its story or provide emotional access to its characters. The movie seems to want to function as a mood piece — perhaps something closer to Bing Liu’s haunting narrative debut Preparation for the Next Life from last year — but there’s so little vitality on the screen you start to wonder, “Isn’t being an accomplished actor enough?”

Punctuated by clunky whiteouts to signify a change of location, the film’s time frame is often blurry and its setting unclear. Many audiences will spend a third of the run time trying to figure out the characters’ relationships. 

The movie opens with Lucila (Anna Díaz, the sole reason to keep watching) being woken by her mother Isabel (Adriana Paz, from Emilia Perez), who instructs her to take care of her little brother before disappearing to Spain. Sometime later, Lucila follows Isabel from Mexico City to Madrid, with her brother Diego (Sergio Bautista) in tow. 

Forced to support the family, Lucila finds work as a nanny, looking after the infant son of a rude, bossy architect (Irene Escolar), while also assuming responsibility for her own increasingly difficult brother Diego (Sergio Bautista), who risks explusion from school if he keeps hitting classmates. 

Impulsively, Lucila follows her friend Jimena (Laura Gómez) to Barcelona in pursuit of independence. She gets herself an English musician boyfriend (Charlie Rowe), while hiding the fact that she does elder-care work and food deliveries from him. Feeling left behind by their neglectful mother and abandoned by his big sister, Diego turns up in Barcelona, but after a disagreement, he tells Lucila that despite all her criticisms of Isabel, she has become just like her.

Things deteriorate for Lucila when she’s unable to pay rent and is kicked out of her shared apartment, but her world completely crumbles when she gets a call informing her of a tragic death in the family. Ignoring her stricken mother’s advice, Lucila decides to go back to Mexico City to mourn with her grandparents (Luisa Huertas and Guillermo Ríos) and other relatives, sneaking the deceased loved one’s ashes into her backpack. 

These are some of the film’s most touching scenes, when Lucila perhaps feels more like she’s part of a family than she has in years. Despite a mentality forged by military service, her abuelo is kind and affectionate, while her straight-shooting abuela gives her the explanation she’s long been denied for her mother’s abandonment, without sugar-coating it.

This concluding stretch also explains — more literally than emotionally — the original title of Navarro’s novel, Ash in the Mouth. But the impression throughout is of a complex work of fiction distilled down to broad-strokes plot machinations, to the exclusion of meaningful character insight. It’s a movie that manages to be both intimate and uninvolving, though that’s no fault of the very capable actors. Perhaps it was chopped up in the edit in a bid to push the story forward, while inadertently gutting it.

The screenplay barely touches on some of what would appear to have been important themes, or at least vivid background texture, in the book. The stigmatization of Mexican immigrants, treated by the Spanish as cultural and class inferiors, is limited to the curt disdain of one nightmare employer, or to Lucila on the street in Barcelona contemplating a flyer for an accelerated Catalan language course. 

The crime and socioeconomic factors driving Mexicans to seek opportunities abroad are articulated only in a chaotic nighttime scene in which a gang declaring itself in graffiti to be “The New School” terrorizes the peaceful neighborhood where Lucila’s grandparents live. We are left to assume this is a drug cartel making its menacing presence felt.

In the end, the most effective moments are those in which we observe Lucila showing genuine affection for the people in her care — rolling on a bed laughing with a happy baby or tenderly bathing a Spanish family’s neglected grandmother. But the movie lacks fluidity; its fussily fragmented approach ultimately just leaves us with pieces that don’t add up to much.