Hazy summer nights lit with neon lights. Salty mist, smoky cigarettes. Peeking midriffs, lanky arms and torsos dripping with seawater; undulating in a cheap motel. This is the furtive, nocturnal, sensory world of Frankie (Harris Dickinson), effortlessly spun like sugar by writer-director Eliza Hittman in her sophomore feature, “Beach Rats.” Frankie and his friends, a group of young Coney Island hoodlums without much to do, spend their evenings trolling the boardwalk for babes and bud.

We quickly discover that Frankie is interested, sexually, in men, as he tentatively explores local gay dating sites, eventually meeting up with a few men for hookups. But he is deeply closeted within his bubble of teenage machismo, and so his boardwalk flirtation, Simone (Madeline Weinstein) becomes his beard, all while he’s venturing into anonymous sexual relationships with older men.

This is essentially the entire plot of “Beach Rats,” but the film is riveting and deeply compelling with the one-two punch of Dickinson’s astonishing performance and Hittman’s direction — awarded with the directing prize at Sundance. Tension courses throughout, as Frankie leads his double life. We’re concerned his secret will be discovered, even as he tentatively reveals parts of himself to his friends, and we’re worried about whether he’ll do the right thing when confronted with conflict, as he makes the wrong choices again and again.

Hittman has a lyrical, dreamy aesthetic, also seen in her debut feature, “It Felt Like Love,” a similar tale of sexual coming of age in Brooklyn. She and cinematographer Helene Louvart use mood, environment and lighting masterfully. The feeling of spontaneity imbued throughout, the sense of illicitly snatched moments, conceals the specificity of the work.

A theater and television actor from London, Dickinson makes his film debut in “Beach Rats,” and he is in almost every frame of the film. His impossible beauty adds to the tension, sexual and otherwise, throughout, and allows for Frankie’s ease of existence in this liminal space — between teenager and man, between straight and gay.

The slow-motion car crash of Frankie’s destiny rolls inevitably to a sickening conclusion. If ever, at times, he seemed vulnerable to violence or exploitation, all along the only threat to him is himself. While Hittman explores his story with a deep sense of interiority and empathy, she never lets Frankie off the hook. Dickinson’s darting eyes, seemingly shameful, reflect the Coney Island fireworks in a juxtaposition that serves as the thesis of “Beach Rats,” a contrast that lies in the title itself, where beauty and hideousness co-exist.

MOVIE REVIEW

“Beach Rats”

Grade: A

Starring Harris Dickinson, Madeline Weinstein and Kate Hodge. Directed by Eliza Hittman.

Rated R for strong sexual content, graphic nudity, drug use and language. Check listings for theaters. 1 hour, 35 minutes.

Bottom line: A coming-of-age tale about coming out of the closet