Everything, Everything

Next off the assembly line of big-screen adaptations from young-adult novels comes Everything, Everything — a teenage romance that’s not for everyone, everyone.

The target demographic seems to be adolescent girls and fans of the book by Nicola Yoon, who might be more accepting of the cute contrivances and more willing to overlook the film’s sugary sentimentality and abundant narrative flaws.

“My immune system sucks.” That’s how Maddy (Amandla Stenberg) describes her affliction, diagnosed by her physician mother (Anika Noni Rose) as severe combined immunodeficiency, which has caused her to remain inside her carefully sanitized suburban Los Angeles home throughout her 17 years. Venturing outside apparently puts her at risk of disease and death, leaving her nurse (Ana de la Reguera) as the only source of meaningful interaction.

Enter Olly (Nick Robinson), an outsider whose family has moved in next door. The two exchange glances through their respective bedroom windows, and deepen their relationship using social media. Eventually, they give into temptation and arrange to meet in person behind the back of Maddy’s mother, who forbids physical contact.

The screenplay by Mills Goodloe (The Age of Adaline) masquerades as life-affirming until a late revelation will change the perspective of the uninitiated. Meanwhile, director Stella Meghie (Jean of the Joneses) employs a slick visual approach that includes an imaginative re-enactment of text-message conversations through fantasy sequences.

Stenberg (The Hunger Games) bolsters the material with an expressive portrayal that brings depth and complexity to a character who craves normalcy, not pity, and remains upbeat without dwelling on her predicament.

She also generates a reasonable chemistry with Robinson (The Kings of Summer) that makes the film charming in spots, even after a cheesy meet-cute involving a wayward Bundt cake. In fact, their romantic rapport adds a layer of authenticity to a film that otherwise indulges in emotionally manipulative tactics — from intrusive music, to trivialized details about Maddy’s affliction, to increasingly ridiculous plot twists that cause the whole enterprise to fly off the rails in the final act.

What starts out as a reasonably fresh take on stories about debilitating illnesses and unrequited young love winds up as a heavy-handed melodrama that lacks the courage to follow through on its convictions.

Rated PG-13, 96 minutes.