I’d been anticipating Barry Jenkins’sophomore film, having long remembered the small pleasures of his promising debut as a writer/director, the romantic drama Medicine for Melancholy, which played as part of 2008’s Independent Film Festival Boston. As enjoyable as that little-seen feature was, however, it barely prepared me for the power of his latest picture, Moonlight, a drama spread across three distinct acts, each focused on the same character, first as a child (Alex R. Hibbert), then a teen (Ashton Sanders) and finally a man (Trevante Rhodes). Each chapter of this story would function as a strong short film if viewed independently. But the cumulative effect might just blindside you.

Jenkins introduces us to Little (Hibbert) when he’s a poor black youth living in Miami’s Liberty City housing projects. This isn’t the glowing neon heaven that we’re used to seeing in the movies; it’s a place that Jenkins knows intimately. He grew up here, as did Tarell Alvin McCraney, whose autobiographical play, In Moonlight Black Boys Look Blue, Jenkins has rearranged and used as the jumping-off point for his script. But before we meet Little, Jenkins and his indispensable cinematographer, James Laxton (whose monochromatic work on Medicine for Melancholy has blossomed into a rich and colorful palette here), pan their camera around Juan (Mahershala Ali from Netflix’s Luke Cage), a local drug dealer who will become a major influence on Little’s life.

When Little is chased by neighborhood bullies into a “dope hole,” Juan rescues the introverted 9-year-old from the dilapidated old building, offering to buy the boy lunch. Gradually, Juan and his girlfriend Teresa (R&B singer Janelle Monáe in a strong acting debut) become surrogate parents to Little, who only has one friend his own age, Kevin (Jaden Piner). This doesn’t sit well with Paula (a stunning Naomie Harris), Little’s single mother, an addict who’s hooked on the junk that Juan peddles. Paula struggles to be a good parent, but she can’t help taking out the resentment she feels toward Juan and Teresa on her quiet, “different” child.

Exactly how different, we’re about to discover, as Little breaks his usual silence just long enough to ask Juan, “What’s a faggot?” Calmly and without judgment, Juan explains, “It’s a word people use to make gay people feel bad.” The boy then inquires, “Am I a faggot?” Juan warmly replies, “You might be gay, but you’re not a faggot. At some point,” he continues, “you gotta decide for yourself who you wanna be.”

The second act jumps ahead as we view Little as a high school student now going by his given name, Chiron (Sanders). He’s still being bullied, not only by Terrel (Patrick Decile), the school hooligan, but also by his mother, whose drug use has spiraled out of control. Occasionally—and to great effect—Jenkins uses the elegant string music of composer Nicholas Britell to drown out all other sounds, including Paula’s rage as she screams at her passive son, who’s having a very bad day when we first see him as a teenager. Nightfall improves things, however, as Chiron sits alone at his favorite spot on the beach where Juan once taught him to swim. Soon, he’s surprised to be joined by Kevin (now played by Jharrel Jerome), who sits on the sand beside him and offers him a drag on his blunt. As the two sit and smoke under the moonlight, the stage is set for some teenage experimentation, and Chiron’s first sexual experience.

His happiness is short-lived, however. The next time he sees Kevin, the object of Chiron’s affection is being prodded by Terrel to punch Chiron’s “faggot ass.” When Terrel and his buddies take over and continue to beat the buckled-over, bleeding Chiron, Britell’s score once again overtakes the soundtrack, and you’re thankful not to have to listen to the sound of the devastating blows.

When a school administrator unsuccessfully attempts to convince Chiron to identify his attackers, the fragile teen breaks down—until he simply breaks, single-minded in his silent determination to seek surprising, violent revenge against Terrel. In the aftermath, Chiron is taken from school in handcuffs, locking eyes with Kevin for what could be the last time. Once again, the music takes over, only this time, the sound Britell produces is akin to an orchestra warming up—a fitting motif, since Chiron’s rebirth in the film’s third and final chapter is about to begin.

You may also be surprised by the physical transformation that Chiron has undertaken when next we see him. Now an adult living in Atlanta, he’s known as “Black,” the nickname Kevin gave him when they were children. Black’s once-fragile frame has bulked up and hardened—but his heart and mind may not have followed suit, as we discover when a call wakes him in the middle of the night. The voice on the other end of the phone belongs to Kevin, who’s played in a tremendously warm, delicate performance by André Holland (of Cinemax’s The Knick). This short conversation, filled with more pregnant pauses than dialogue, will set Black toward an oceanside date with fate, under the glow of the moonlight that illuminates the place where he finally embraces who he wants to be—and the boy finally becomes a man. Bring tissues.

Moonlight   ****

Starring Mahershala Ali, Shariff Earp, Alex Hibbert, Ashton Sanders, Trevante Rhodes, Janelle Monáe, Naomie Harris, Patrick Decile, Jaden Piner, Jharrel Jerome and André Holland. Directed by Barry Jenkins. Written by Jenkins, based on a play by Tarell Alvin McCraney. At Boston Common, Coolidge Corner and Kendall Square.