Devon DeWitt (Meghann Fahy, "The White Lotus") desperately needs help to care for her father Bruce (Bill Camp) who's suffering from dementia, and reaches out to the obvious helpmate — her own sister, Simone (Milly Alcock, "House of the Dragon"). But Simone has left their hardscrabble past back in Buffalo in the dust, to become personal assistant to the eccentric Michaela Kell (Julianne Moore) — married to hedge fund billionaire Peter Kell (Kevin Bacon) — who devotes her energy to caring for injured raptors and other birdlife from the sanctuary that adjoins their spectacular estate. When Devon heads to the island to pry her sister away from Michaela and all those birds, things get messy: Simone and her boss are planning a lavish gala for her richest and closest pals which Devon is about to crash. The call goes out to the Kells' estate manager, Jose (Felix Solis, "Ozark") to avert impending disaster.

Simone, meanwhile, has a few secrets of her own that she's kept from Michaela — her past, and her boyfriend, Ethan (Glenn Howerton), the rich guy next door.

This five-parter — based on a play by Molly Smith Metzler (Netflix's "Maid") — is apparently set on Nantucket but filmed mostly on Long Island.

"Sirens" was filmed in Caumsett State Historic Park Preserve, and other spots in Lloyd Harbor, as well as points much farther east in Southold, which means — well, you get the picture — this five-partner is a beauty. It's that sort of beauty that relentlessly draws the eye from the foreground of the screen, to the background, where all those midsummer blues and greens, mauves and turquoises, will remind you of what you really ought to be doing on this Memorial Day weekend, weather permitting — get outside. The foreground is alluring enough too, also aswirl in pastel colors — Llly Pulitzer and Vineyard Vines are the predominant fashion statements here, with everyone looking particularly fabulous.

Turn the sound off to luxuriate in how the one percent live; turn it back on for the reality check. "Sirens" has mastered the overall aesthetic, if not quite the overall story that it's adorned so handsomely. Think of this as a pretty picture stretched to fit a far-too-large canvas, with all the usual tricks enlisted to fill out these five overburdened hours.

That's a shame because if the plot matched what's on screen, this could almost be "The Perfect Couple," a compulsively watchable Netflix mini from 2024 starring Nicole Kidman and Liev Schreiber and which also luxuriated in the same general filthy-rich-behaving-badly-in-Nantucket idea.

Instead, it's a bore. That's the bigger shame because "Sirens" is potentially interesting — a character study about trauma and how it disfigures people, and how they find their way out of the darkness. Devon's attempts have turned self-destructive — risky, compulsive sexual encounters, with alcohol as self-medication — while Simone has erased that traumatic past to become Michaela's Stepford assistant and surrogate daughter. Meanwhile, Michaela has erased her own past too, to become Kell's Stepford wife. She could never have children of her own and instead blindly grasps at anything — those birds, Simone — to fill her maternal emptiness.

This is the stuff of tragedy except "Sirens" doesn't want a tragedy. It wants a comedy, a trifle, a murder/mystery, an eat-the-rich satire on the shallow lives of those over-privileged and well-attired few.

Honestly, I'm not sure what "Sirens" wants and I suspect pretty, colorful, padded "Sirens" doesn't know either. The biggest shame of all.

A big, beautiful bore.