Bittersweet

The spark between two soon-to-be lovers ignites inside a Latin nightclub in New York City, as the pair dance with clumsy playfulness to the Spanish romantic ballad “Un Velero Llamado Libertad” (A Sailboat Named Freedom). Their origins and struggles couldn’t be more disparate: She is an undocumented immigrant who’s part of China’s persecuted Uyghur ethnic minority; he’s a white Army veteran with no clear direction and a chronic case of PTSD.

Holding on their comforting stares and unspoken exchanges with only Emile Mosseri’s sonic drizzle of a score as company, filmmaker Bing Liu (best known for his Oscar-nominated documentary “Minding the Gap”) delicately traces their blossoming and improbable romance in his first foray into fiction, “Preparation for the Next Life,” based on Atticus Lish’s 2014 novel of the same name, written for the screen by Martyna Majok.

Neither the dangerously rampant mental health afflictions among military folk nor the dehumanization and exploitation of undocumented people have gone unexplored in American cinema. However, the character-driven humanism of “Preparation” makes these topics feel experientially explored through concrete events and interactions, rather than simply superimposed on a narrative. The drama observes how the circumstances shape their relationship, turning the mundane into their battleground.

What tethers Aishe (Sebiye Behtiyar) and Skinner (Fred Hechinger) so intensely to one another, despite their seemingly incompatible backgrounds, is the shared feeling that they don’t naturally belong to the world in front of them. Isolated while surrounded by millions of people, they find in one another a life-affirming anchor. At one point, early in their courtship, the camera moves through layers of people to find them silently licking McDonald’s soft-serve cones, visually pushing everyone aside to make them the center of it all.

During the honeymoon phase of their relationship — which will become a blistering chronicle of impossible love and resilience in modern America — Liu and cinematographer Ante Cheng capture the couple and the city with an ebullient dynamism, making the urban vistas and the crowded streets of Chinatown seem almost idyllic. But that aura of possibility begins to fade when the less pleasant edges of their respective realties come to light.

At first, their bond hinges on physicality. They dare one another to do pushups, to chug down beers. Aisha prides herself on her body’s fortitude, earned through years of training with her soldier father. Narrated flashbacks to her childhood in the vast landscapes of China reveal a yearning for a previous existence she can’t go back to. Her “next life” is the here and now in the U.S., where a steadfast conviction to appear indestructible to others conceals her inner fragility.

Meanwhile, there’s an endearing naiveté to Hechinger’s performance. Skinner moves through the world with a cautious eagerness to connect, desperate for the feeling of being acknowledged. His awkward body language and soft gaze exhibit a boyish tenderness, clouded only by the erratic outbursts of his condition. That he’s far from a muscular, disaffected, overtly macho-type — yet wishes to transform himself into a bodybuilder — makes for a more convincingly relatable figure. And yet, Skinner’s gentle, unsophisticated demeanor — which attracts Aishe to him — also renders him limited in his understanding of her situation. The stakes of her everyday plight escape his worldview.

That’s the crossroads they must face. How can she compel him to truly see her? More than once, Aishe looks at Skinner with a rather specific expression, not one of condescension or pity, but charged with a genuine desire to believe that they can build a life together, that their painful present can change. In fact, it’s the potency of her still visage that makes Behtiyar (an Uyghur actress in her first feature) an acting revelation. Behtiyar plays the assertive Aishe as a young woman unwilling to surrender her dignity or dwell on anguish.

Thanks to its terrific stars and Liu’s patient direction, which luxuriates in the smallest of gestures, “Preparation” transcends its most predictable beats, such as Aishe’s encounter with immigration authorities or Skinner’s inevitable, ignorant, final lashing-out episode.

Late in “Preparation,” Aishe walks into a mosque. There, an Inman speaks to her about how the tribulations and suffering we experience while alive will be rewarded in the hereafter. But the foundation of her defiance lies in trying to mine purpose, and perhaps even joy out of this existence. It’s a sorrowful realization for Aishe that her most invaluable asset is her ability to flee, to readapt, to not become beholden to any place or person in order to survive.

Thus, when the song that first brought her and Skinner together returns as a motif for yearning, one can comprehend that loss is her only constant — at least in this current life.