It’s a murder mystery set among the filthy-rich/cash poor on Cape Cod, a tale of parties and endless infidelities in which almost everybody has some posh name or nickname — “Tag, Merritt, Greer,” “Shooter” — and almost everybody seems like a suspect.

Netflix’s “The Perfect Couple” is perfectly trashy and predictably unpredictable as it spends six episodes setting up one “HE did it” or “Maybe SHE did it” after another.

Built around Oscar winner Nicole Kidman and Liev Schreiber, thisJenna Lamia (“Good Girls,” “Awkward”) production is practically a parody of a “beach book” turned murder mystery movie, dolling everybody up and sketching characters in as “types” — the stoner womanizing patriarch, the entitled, broke bro son (Jack Reynor), his bitchy-pregnant wife (Dakota Fanning) who married money. She thought.

“The key to this family is to just stay on the periphery, where it’s safe.”

And amid the accusations, intrigues, police interrogations and flashbacks to the rehearsal dinner/party where the crime was committed, and to earlier parties and arguments, “Couple” shows off beachside mansion life, vamps a version of “how old money” acts and showcases the difference between good plastic surgery (Kidman) and bad (Isabella Adjani).

Working class Amelia (Eve Hewson) is about to marry Benji Winbury (Billie Howle). Mother of the groom Greer (Kidman) is frosty but accepting. She, too, married Winbury money. But she’s had to prop up the clan and her louche husband Tag (Schreiber) by writing fiction of the romance novel persuasion.

But Amelia’s model-thin influencer maid of honor Merritt Monaco (Meghann Fahy) turns up dead at that rehearsal dinner. People have motives. People have injuries, suggesting involvement. People have access to drugs that were found in her system.

Male people have the ability to put her in the condition she was in at her death — pregnant.

Who could have done it? Well, any of them.

The Nantucket police chief (Michael Beach) is so cowed by Winbury cash that the State sends an abrasive investigator (Donna Lynne Champlin) to supervise this case. Wait’ll she finds out the chief’s daughter is sneaking around with a Winbury teen.

And on and on the complications, interrelationships and suspicions go, with character after character subjected to scrutiny, “custody” and accusations. They sneak around and sleep around, rummage for clues or to cover their tracks, scheme and cast asperions and deflect blame.

“Dont get caught in Greer’s crosshairs!”

Even Kidman and Schreiber have trouble making their characters two, much less three dimensional. The lesser lights in the cast have no prayer.

There’s nobody here to identify with, nobody to root for, even the bride, who gets an E-Type Jaguar for her troubles.

So like any soap opera, you hunt for villains to relish. But even they — the foreign friend who’s slept with generations of Winburys (Adjani), the most abrasive heir, the loutish Tag, the controlling matriarch, the judgmental housekeeper — are lacking the snap of lip-smacking villainy.

“The Perfect Couple” has a thesis no one buys into, a dated grasp of media and scandal in the 2020s and characters that are more cartoons than flesh and blood folks with foibles. It’s a TV version of a bad “beach book,” making one wish one had spent these six hours doing something else, preferably on a beach.

Rating: TV-MA, violence, sex, profanity

Cast: Nicole Kidman, Liev Schreiber, Eve Hewson, Jack Reynor, Isabelle Adjani, Ishaan Khatter, Michael Beach, Meghann Fahy, Billy Howie and Dakota Fanning.

Credits: Created by Jenna Lamia. A Netflix release.

Running time: Six episodes @:50-63 minutes each