Were Mikita Brottman’s “Guilty Creatures” a work of fiction, the plot would be deemed clichéd: an affair, a missing body presumed eaten by alligators, a million-dollar life insurance payout and a beautiful widow who quickly finds love in the arms of her dead husband’s newly divorced best friend.

“Nobody believed Mike had drowned in Lake Seminole,” the author and psychoanalyst Brottman establishes, before dispensing with the missing body as the least interesting part of the story and turning her attention instead to the 17 years between Mike Williams’s disappearance and the conviction of his killers — justice (mostly) served.

The book opens with feathered bangs and hunting rifles: a 1988 yearbook from North Florida Christian High, a private Baptist school, “formerly a segregation academy and almost entirely white.”

Here is where we get our first glimpse of the main players — the doomed victim, “quarterback Jerry Michael Williams, always known as Mike”; his girlfriend, Denise Merrell, three rows above; and to his left, Mike’s “best buddy,” Brian Winchester, along with Brian’s girlfriend, Kathy.

“The boys played football, the girls cheered them on,” Brottman tells us. Their world was as narrow as the yearbook, its rules dictated by strict church doctrine and their conservative families. After high school, all four attended Florida State University, living at home until the storybook inevitable. “Both couples married in 1994. Church weddings. Cake and lemonade.”

Right on cue, each pair had a child. And then, on Dec. 16, 2000 — his sixth wedding anniversary — Mike disappeared during a duck-hunting trip to Lake Seminole. Initially, alligators were the presumed suspects, or at least blamed for the absence of a body.

At this point, the narrative doubles back, intent on exposing the unseemly truths behind the pious veneer of “first-generation suburbia, an ecosystem of oak-shaded, brick-and-mortar homes, cul-de-sacs, beltways, megachurches, outlet malls and big-box stores — clean, prosperous, exclusive, safe and repressed.”

In reality, after their shared Southern Baptist upbringings, the two young couples had let loose in a kind of fundamentalist rumspringa; “they skipped church, tried drugs, went to strip clubs.” After drinking all day, “Brian would get Kathy and Denise to take their clothes off and fool around while he took Polaroids.”

Ultimately, two of them — Kathy and Mike — had their fill of this relative libertinism. A quote from Kathy’s 2018 trial deposition says it best: “Mike and I were kind of, like, this is fun or whatever, but we were ready to have kids.”

Enter adultery. Denise and Brian continued meeting in secret. “Like teenagers, they did it in the car, getting to know places they wouldn’t be disturbed. Church parking lots were good for that, ironically.”

Brottman posits that their faith took divorce off the table, but this is hardly convincing; the million-dollar life insurance policy that Brian sold to his best friend a few months before his disappearance seems a far more compelling motive.

Brottman shines in her depiction of the victim’s mother, Cheryl — busy with “running her day care, babysitting her granddaughter and feeding 20 feral cats” — who refuses to allow her son’s disappearance to be forgotten and is rendered one of the few truly complex characters in the book.

And Brottman’s treatment of Reddit, the Websleuths forums and commentary from self-anointed YouTube experts makes for a particularly damning portrait of our culture’s consumption of crime — though this point would have cut more sharply had the writer attributed these quotes in the text rather than sourcing them in the notes.

In Brottman’s earlier books, she used dead bodies as lenses to reflect a larger story: “An Unexplained Death” explored the link between invisibility and suicide, and “Couple Found Slain” focused on the disaster of our country’s forensic psych wards. In both, her obsession with and proximity to the central crime drives the narrative — one victim is found in Brottman’s apartment building; she meets a murderer in a reading group she oversees in his psychiatric hospital. In “Guilty Creatures,” however, this level of personal obsession never takes hold, aside from the murder-map-style evidence marshaling (which can border on tedious). It never becomes clear why she is drawn to this particular crime, or what larger story she wants to tell.

Polyamory, open marriage, expansive desire and divorce are all current best-seller fodder, making the foursome’s porn-fueled, vanilla-hetero-fantasy romps feel more quaint than salacious.

The power of the Baptist Church is barely examined, the poison of the American dream merely gestured at, the uniqueness of Florida sketched only briefly.

In the introduction to his masterly collection “Killings,” Calvin Trillin writes, “These stories are meant to be more about how Americans lived than about how some of them died.” The cauldron of fornication, fundamentalism and Florida Man high jinks is a steamy promise; ultimately “the alligators made a great punchline.” But, really, these reptiles are simply a distraction from the actual coldblooded monster here, which may be the pressures of perfection itself.