Let’s start off, as most good books do, with an inciting incident. In this case, that’s the arrival of an 87,000-word manuscript, an unpublished novel, in someone’s email inbox. The title of the document is “Bad Summer People”, and the setting of the book seems familiar to the person who receives the email. Some of the character names do, too. Because of this, the document gets forwarded to someone else who may find it interesting. Who then sends it to another person. And another. Eventually, this unpublished work causes a cascade of small-town mayhem, ending up as a tabloid story with a headline that reads “Media exec’s novel about murder, sex and lies in the moneyed town of Saltaire has sent residents into a spin.”

Sounds like the plot of a good beach read, right? Well, unfortunately for the media exec in question – me – that juicy plotline happened in real life, not between the pages of a book.

The tale of my most dramatic summer starts the summer before that. That July, I was staying with my husband and sons at my parents’ beach house on Fire Island, off the coast of Long Island, in a tiny village called Saltaire, where I’d spent all my childhood summers. I was inspired by the setting: an insular place filled with wealthy New Yorkers, where everyone knows everyone, and everyone knows everyone’s business. You can only access the island via ferry; there are no cars, only boardwalks; and families there have owned their houses for generations. What a perfect place for a murder mystery!

I wrote the novel while sitting in my parents’ front porch, overlooking the Great South Bay. I used “Saltaire” in the draft, and I named characters after townspeople who happened to be riding by on their bikes, planning to change the names if the book ever saw the light of day (I’d never written fiction before, so figured this possibility was slight). The citizens of Bad Summer People were heightened versions of NYC’s elite: finance bros, type-A stay-at-home moms, and the strivers who surround them. The book was social satire, with a sprinkling of mystery and a dash of White Lotus escapism. I was thrilled when Bad Summer People sold to a publisher. I figured everyone in Saltaire would think it was hilarious.

Fast forward to the following summer, my book still a year away from publication. The novel had recently been sent to production companies, with the TV rights eventually going to Amazon Prime. But during that process, the draft had come across the desk of someone who had then sent the unedited, unpublished document to a relative living in Saltaire. The relative had read it and sent it to someone else. The manuscript was quickly circulated around town, with residents at one point passing around printed pages stuffed into a paper bag. Eventually I got wind of this. A family friend had approached my sister on the tennis courts with a chuckle and said: “I heard my wife dies in your sister’s book. I hope she falls off the tennis deck.” I immediately sent my agent a panicked email with the subject line: “Apparently people here are sending round my book?” She didn’t seem too concerned. All buzz is good buzz, I guess.

Suddenly, it seemed everyone was whispering about me. Wondering who characters were based on. Gossiping about the plot, which involves stealing, fraud and cheating, as if those events had happened in the real world and not just in my head. My book was the talk of the town, and as someone more comfortable on the fringes, I didn’t enjoy the attention.

And that’s when things started getting weird. I don’t want to call myself a witch (though I can’t speak for others), but after the village got its hands on my book, certain incidents began occurring that resembled the fictional action of Bad Summer People. A fight broke out during the mixed doubles tennis tournament, with shouting, threats of violence and then sheepish apologies afterwards. There were rumours of marital affairs. A complaint was made that the tennis players were too “cosy” with yacht club members. The summer had a fizzy, combustible feel, unlike any other I could remember. Had I somehow conjured all of this into existence? As a joke, someone put a wooden cross at the real location of the imaginary murder in my novel. An acquaintance drunkenly confessed to me that she’d read the leaked manuscript and had said to her husband: “Isn’t it sad that Mr so-and-so is dead?” referring to a character in the book who she’d assumed was a specific person in town. Her husband assured her that this man was alive and well.

You can only access Fire Island via ferry; there are no cars – it’s the perfect place for a murder mystery

Eventually, word spread beyond Fire Island, and a reporter arrived on our shores, taking the ferry over to investigate this rich-person-comedy-of-errors. She stood at the store and asked people if they’d chat about me, my family and my book. She attended a tennis match, walked the boardwalks, and later published a story with the headline, “Bad Summer People, a salacious summer read, is causing chaos in a Fire Island town full of wealthy Manhattanites”. The day it came out, I rode around town on my bike, sunglasses on, smile frozen in place, wondering which of my neighbours, which of my friends, which of my parents’ friends, had provided anonymous quotes for the piece. A tabloid picked up the story soon after, and for a glorious minute, my book shot up on Amazon’s sales ranking. A silver lining indeed. If you’re wondering if anyone died in real life, the answer is a resounding “no”. Though my mum nearly murdered me for all the headaches I caused her.

The summer ended shortly thereafter, thank God, and everyone in Saltaire retreated to their winter homes and winter problems, putting me and my beach read out of their thoughts. I went back to Manhattan, back to my day job in the media, back to waiting months and months for Bad Summer People to come out. Of course, in the version you’ll read, the names have all been changed. Saltaire has been transformed into “Salcombe”, a town name I found after Googling “English seaside villages”. Salcombe looks like a charming place, though I have no plans to visit, for its own good. Who knows what kind of unintentional black magic I may unleash there?

If there’s a moral to this tale, beyond never naming a fictional character after a person you know, it’s that people love to put themselves at the centre of any story. For me, the most illuminating part was coming into contact with people who felt insulted because they weren’t in the novel. “Why am I not in it?” one neighbour complained. “I feel like I make myself a little bit known around here.”

I’m not sure what to expect from this summer, but I’m hoping for calmer waters. In honour of Bad Summer People’s release, my mother and sister are hosting a book party for me at the yacht club. We’re inviting the entire town. It’ll be a fitting final chapter to a strange sequence of events. Perhaps there, and possibly for evermore, people in Saltaire will look at me with a slight side-eye. Clinking my glass of champagne while wondering if I’m gathering intel for my next book. And who knows? Maybe I am.

Bad Summer People by Emma Rosenblum is published by Penguin. To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply.