Miami, Florida is the US at its extreme. Ostentatious wealth is everywhere, some legal, some very illegal, most of it in a grey area between the two. All of it is propped up by the hard work and cherished dreams of immigrants, people whose fight for a better life is getting harder – those few who make it to the top having to decide if, now they are no longer being exploited, they are willing to exploit others.

All that provides the serious subtext for MIA, a new drama created by Bill Dubuque (Ozark). But any thoughtful treatment of the immigrant experience it might have to offer is overwhelmed by the sheer silliness of the main story, a revenge thriller starring Shannon Gisela as Etta Tiger Jonze, a woman in her early 20s whose entire family is slaughtered by a drug cartel. Raging with grief and with nothing to lose, Etta restarts from zero, lying low in Miami’s Haitian community while plotting to kill precisely 12 gangsters: the bad guys she witnessed murdering her loved ones.

Like Ozark, MIA spends the whole first episode on backstory, namely the Jonzes’ annihilation. But the opener here is much less entertaining than Ozark’s was, since it’s full of the awkward dialogue and convenient plotting that dogs the rest of the series (there’s a piece of foreshadowing that’s as subtle as being mauled by a 12ft alligator), as it forlornly asks us to invest in characters who are doomed. You might as well skip it and make do with the “Previously …” montage at the start of the second instalment: by then, Etta has been taken in by smart, forthright Haitian immigrant Lovely (Brittany Adebumola).

Etta and Lovely join the bottom layer of Miami society, scoring jobs as cleaners and maids. They quickly discover that they have no rights or recourse if something goes wrong, a problem made worse by Etta’s refusal to remain passive in the face of injustice – this trait being what helped to get her family killed. But as a US citizen, Etta has several advantages: she grew up in the city, so she has local knowledge, even if she has lost her former social status. Also, rather than just being smart, resourceful and verbally agile, as we initially thought, she has a photographic memory! That really comes in handy, and not just when she has to remember the faces of the dirty dozen she has vowed to exterminate.

Etta’s perfect recall of detail is not the only way in which MIA, having created a hero who faces impossible odds, cheats by giving her unlikely leg-ups. Her mother had a sister from whom she was estranged, but who is in Miami and can be tracked down. Wouldn’t you know, she turns out to be a badass who runs a nightclub frequented by gangsters! It’s the ideal place for Etta to start circling her prey.

The other job Etta and Lovely find is at a motel run by Lena (Tovah Feldshuh), who seems like any other pitiless employer until Etta bonds with her by going full Sherlock and picking up on tiny visual clues to discern that she is the daughter of Holocaust victims. Now a friend, Lena proves to be another badass with unusual skills and resources! Etta’s not so unlucky after all.

In a swankier part of town, meanwhile, the Rojas cartel are unaware that they have failed to kill all the Jonzes, so they busy themselves with squabbling over how to progress the business in the absence of their recently deceased patriarch, a wise leader who entrusted his legacy to his unwise children. “We need another revenue stream – one with a similar profit margin!” says hot-headed Mateo (Maurice Compte), as he talks his cautious brother Samuel (Gerardo Celasco) into giving people-trafficking a whirl. Their sister Caroline (Marta Milans) runs the ostensibly legitimate part of the operation, a real estate company that plans to plonk a crass skyscraper in the middle of Little Haiti.

In a show that swings between boring and ludicrous, the bad guys offer most of the dullness, with their boilerplate sibling rivalry and their monotonous gunning down of collaborators whom Mateo perceives to be a risk. An ineffectual Cary Elwes makes his contribution as a kooky gumshoe who is investigating the Jonze killings, and who seems to have ambled in by mistake from a lackadaisical shaggy-dog thriller that was filming on the lot next door.

The “found family” Etta gathers when she’s at her lowest point is the soul of MIA, but that, too, gets lost when she starts ticking off her targets. There’s one more big, silly twist at the end that begs for a second season. By then, any reason to see this as more than dispensable fluff has been thoroughly killed off.