Coincidentally, this May brings us two limited series about broken, emotionally traumatized, and estranged sisters who aim to make amends for their troubled past. First in line (and our subject) is Netflix’s five-episode miniseries, “Sirens,” which blurs the lines between dark comedy and searing familial drama through a familiar vibe that dutifully resembles HBO’s “The White Lotus” (and yes, we reviewed Season 3). “Sirens” vehemently tries to carve out its own identity in the rapidly growing “eat-the-rich” subgenre, too, with mixed results. It’ll also be hard to avoid comparing it to Amazon Prime’s “The Better Sister” (which premieres a week after “Sirens”) that thematically lands itself in the same ballpark but with a much more effective dramatic approach. But where “Sirens” can distinguish itself from that limited series is its often brash and scathing humor. It delivers some hilarious and refreshingly upbeat moments in an otherwise overstuffed and tonally inconsistent show that can never quite decide what it wants to be.

Devon (Meghann Fahy) is a broke, recovering alcoholic and 30-something gal from Buffalo, New York — working a dead-end job at a fast-food restaurant — who’s struggling to care for her aging dad, Bruce (Bill Camp), who suffers from early-onset dementia. One day, as she arrives home to her father, she finds a sumptuous fruit basket at the door. It’s from her estranged and much younger sister, Simone (Milly Alcock), who’s having the time of her life on a remote island run by billionaires.

Devon gets so worked up over her sibling’s taunting gift that she embarks on a 17-hour journey with not so much as a backpack just so she can scream at Simone’s face about her negligence when it comes to her family. Who’s going to care for her ill dad in her absence, or where did she get the money to jump on a flight and a boat ride, are questions that the script brushes off. This is where the main issue in creator Molly Smith Metzler’s show surfaces head-on. In a sillier, more light-hearted story, these details wouldn’t matter. But in a series that constantly rubs in our faces how many problems and how much life-crushing trauma its characters have been through — still unable to deal with them — this lack of care about particulars immediately smells like trouble. It’s just lazy writing, even if Devon’s trip is essentially nothing but the inciting incident.

Naturally, “Sirens” kicks off when she barges in on the island unannounced and finds her sister in a high society cult. Simone works for Michaela, or Kiki (Julianne Moore), the goddess of this little island — and second wife to billionaire Peter (Kevin Bacon) — with a huge staff of “servants” in an elaborate mansion that could house a small village. Kiki is strange and creepy and villainous, but Simone is completely bewitched by her. As her personal assistant, she fullfils Michaela’s every need even before she can express them. Initially, Devon’s only goal was to ask Simone to come home and ease her burden, but when she sees the eccentric and exploitative nutjobs her sister’s employed by, she makes it her mission to get Simone out of there ASAP.

But to do so, she needs to join the lunacy for a while and unravel a potential murder mystery, navigating among the creeps and lovers and secretive staff employees who make this place a total madhouse.