Thirty-something couple Alex and Emily and their young son, R.J., have been Los Angeles residents for two weeks. They moved to L.A. for Emily’s job, which means it’s the unemployed Alex who takes R.J. to the park to play.

In the park, R.J. befriends the son of L.A. couple Kurt and Charlotte. When Kurt sees the boys playing happily together, he invites Alex, Emily and R.J. to a family pizza night at his place.

What follows, as detailed in “The Overnight,” is a clever, unexpected comedy about motive and manipulation.

The two couples spend the night together after they put their kids to bed in Kurt and Charlotte’s big L.A. house. While the kids are sleeping, the grownups are playing.

This second feature film from writer-director Patrick Brice follows his horror movie “Creep,” which co-starred Mark Duplass, a writer, director, producer, actor and New Orleans native. Duplass and his filmmaker brother, Jay, are the executive producers of “The Overnight.”

The atmosphere in “The Overnight” seamlessly turns from innocent to a bit lurid. The film has horror overtones. Beyond the sunlight, strange things can happen in the dark. That’s certainly true for Alex and Emily and Kurt and Charlotte. Although they’ve all just met, alcohol, the nighttime, a gorgeous swimming pool, a hot tub and even more drinking open the gates for the couples to suddenly share intimate details about their lives.

Brice packs craziness, head-turning oddity and unimagined possibilities into the overnight period during which “The Overnight” takes place. His subversive script works beautifully despite the time and place restrictions he imposes upon himself and his characters.

The director is also a skilled writer of characters. For “The Overnight,” a story featuring only four principal characters, that’s essential.

Alex and Emily, fresh to L.A. as they are, represent a normal couple and typical parents in their 30s with a young child. At first, Kurt and Charlotte seem normal as well, except for their impressive wealth, as evidenced by their gated, walled-in home and huge pool. It almost qualifies as a small mansion or estate.

Brice’s script and direction smoothly maneuver the progression in the two couple’s behavior and activities. He’s an unusually sneaky storyteller. His film evolves into a hybrid of Paul Mazursky’s classic 1969 sexual satire “Bob & Carol & Ted & Alice” and Martin Scorsese’s 1985 nightmarish comedy, “After Hours.”

Brice deserves an award for casting Jason Schwartzman as Kurt, the increasingly eccentric character who initiates the couples’ wild night. Cool, but also passionate when he suspects the moment is right, the dare to let-it-all-hang out Alex is among Schwartzman’s best comic characters.

Playing Kurt’s sly French wife, Charlotte, French actress Judith Godrèche is game for her character’s husband’s shenanigans as well as sly Charlotte’s mischief making.

Co-starring as the former Seattle residents who are shocked and awed by their new neighbors in L.A., Taylor Schilling (“Orange is the New Black”) and Adam Scott (“Parks and Recreation”) are as smartly cast as Schwartzman and Godrèche.

The collision of these seemingly opposite couples, plus Brice’s bold comedy and occasional drama, makes for a night to remember or, maybe even more so, try to forget.