A teenager comes of age in a small Australian town during the 1970s when a 200-ton blue whale gets washed up on a local beach.
Australia, 1975. Wyong Place, a suburb of Nobbys Beach, is a world that revolves around surf mats, baby oil, boxed wine, and the newly-found miracle of Kentucky Fried Chicken. 14-year-old Jeff tries to find his feet in a world changing faster than his hormones as he deals with his crush on shy and sensitive girl-next-door Melissa. When the beach town suddenly hits the spotlight after the body of a 200-ton blue whale washes ashore, Jeff and Melly think it's the biggest thing that ever hit Wallaroo. Meanwhile, something else is washing up on the shores of Australia: the sexual revolution. As parents race to catch up to the changing world and city officials plan to be rid of the whale, it's only a matter of time before things go wrong.—Keith Hall
Jeff Marsh (narrated by Richard Roxburgh, played by Atticus Robb), now a filmmaker, reflects on his childhood: a sun-soaked memory of spending the seventies in Wyong Place, a neighborhood nestled beach-side in the town of Wallaroo, South Australia. He recalls how his own family, consisting of his mother Gale (Asher Keddie), father Bob (Jeremy Sims), and sister Rebecca (often called Bec, played by Chelsea Glaw) intertwined with the neighboring families every weekend; in the best and worst of ways.
The other families introduced include the Hall family, consisting of Keith (Guy Pearce) and his wife Kaye (Kylie Minogue), along with their five children Gerome (Jesse Denyer), Liz (Chelsea Jamieson), Damian (Alex Kotan), Andrew (Jacob Kotan), and Keira (Ava Taylor), and the Jones family, which includes Rick (Julian McMahon), his wife Jo (Radha Mitchell), and their children Cal (James Calder), Liam (later specified to be called Lenore in the present day, played by Ethan Robinson), and Melissa (more often called Melly, played by Darcey Wilson).
On one of many shopping trips with his socialite mother, Jeff attends a showing of Jaws (1975) at the shopping center's cinema, sparking a love for film-making and an eagerness to bring his cinematic ideas to life, opting to constantly record the world around him with the aid of neighborhood kids.
A day at Nobbys Beach proves to be a perfect backdrop for Jeff's brand new idea for a then-unreleased sequel to Jaws. While filming with Damian, Andrew, and Gerome, a 200-pound great blue whale is discovered to have washed up further down the shore. Eager to include the extraordinary event in his film, Jeff joins the crowd of news reporters in filming the massive mammal, nicknamed Chips. Other beach-goers are not quite as impressed, and Jeff, alongside his family, retreats to attend a neighborhood gathering, which Gale and Jo seem particularly anxious to get started.
Melly, who is, like Jeff, forever scarred both emotionally and physically by a shared childhood accident, dreads the upcoming party as she reads about blue whales in her room, much to the annoyance of her mother. As guests begin to arrive with platters of food and bottles of alcohol, Bec voices her suspicions at the level of dress and presentation put on for a seemingly routine get-together. The children, all but Melly, eat while their parents dance outside. Depressed about Chips the Whale, Melly refuses to eat, earning her and the rest of the table a punishment. In an act of solidarity, Jeff finishes her dinner for her, allowing the children to run off and play.
The party starts, and parental negligence is on full display as the children of Wyong Place, going by the self-imposed nickname Death Cheaters, perform dangerous stunts for the camera, and Bec sneaks off with Cal and Lenore to have sex, all unbeknownst to their parents inside. The adults grapple with Gale and Jo's proposal of catching up to the sexual revolution of the seventies with a key party, to which they eventually agree. The children, all except Jeff and Melly, disperse. When attempting to comfort Melly later that night, the pair overhear strange noises downstairs; peeking over to see a swinging party underway.
Gale is paired with Rick, Kaye with Bob and Jo with Keith. The ladder pair becomes reluctant to put a stop to their sexual escapades when Bob calls the party off after a failed attempt to seduce a petrified Kaye. Fighting ensues, and a shocked Melly and Jeff listen from above as the party goes disastrously wrong.
The following morning, Rick accidentally bumps Jeff off of his bike with his car as he's driving his children to school, prompting an awkward moment as clueless children observe the tension between their parents. Jeff and Melly overlook a now-rotting Chips before school, reeling from what they witnessed the night before. In school, the children's teacher Mr. Logan (Marcus Guinane), poses the theory that Chips purposefully beached herself, either out of confusion or depression, an idea Melly seems to connect with. Melly begins to believe Chips died by suicide and refuses to eat or take her anxiety medication, saying she no longer sees the point. While the children wonder what's happened to their parents, little explanation is offered to them in the coming days, as tensions are higher than ever between the residents of the block.
Cal and Lenore cut up and graffiti Chips' corpse, much to Melly's dismay, and Jeff's friendship with Gerome begins to fall apart as the star of his homemade movies turns to bullying him, hanging out with Rooster (Jacob Elordi), Bec, Cal, and Lenore instead.
As the whale decays, so too does Melly's mental health and the relationships of the failed swingers. Gale blames Bob for ruining the party by refusing to have sex with Kaye, Keith accuses Kaye of being an agoraphobic alcoholic, and Rick and Jo argue about her relationship with Keith in front of their children constantly, accidentally punching Melly in the face in one attempt to silence Cal's prodding. Attempting to escape their parents' constant fighting, Jeff and Melly visit the beach to see Chips, and Jeff tries desperately to get her to begin eating once more with no such luck.
On Cracker Night (Australia's now-banned, fireworks-themed celebration of New Year's Eve), the Marsh family dog Sandy is killed in a fireworks accident. Jeff narrates a brief explanation of Sandy's gluttonous upbringing, the Hall family's tragic pet dog Doody and habit of keeping dangerous animals in their backyard, and the Jones' mistreated tortuous Tommy, before the families of Wyong Place reunite for her funeral, making the ultimate decision to punish their children to offset their personal guilt. All efforts to ignore the tension between both the children and the adults fail; with the Death Cheaters unofficially disbanding and the parents getting into a petty yelling match about their activities as one-time swingers, sending the families storming off once again.
As Jeff attempts to continue the Death Cheaters filmmaking mission without Gerome, tensions come to a head over the next few days, with the adults pulling petty pranks on each other to get revenge for their once-consensual infidelity. The final straw comes when Gale urinates on Kaye's daughter Keira in an attempt at revenge on Kaye for pulling Bob's keys at the party. The police are called and a restraining order is suggested and rejected, inspiring Jeff and Melly to spark a plan to free Tommy and flee their homes, plotting to run away to Melbourne to escape their home lives. The pair quickly turn back to stock up on clothing and supplies, only to be caught by their respective fathers mid-kiss and subsequently grounded.
The following morning, Nigel Frost (Caleb Monk), a young boy left disabled after an umbrella-related accident at Bob's hands years prior knocks on his door, asking for donations to the Give Kids a Second Chance charity. The name brings a revelation upon Bob, who asks them to reconvene one last time and finally reach a conclusion: after setting such a horrible example for their children, rewarding them may be more beneficial than punishing them. Kaye reasons that their generation was raised on fear and discipline, and by supplying their children with anything they want and not restricting information on typically taboo subject matter like sex and alcohol, they will grow to be the opposite of their irresponsible, repressed parents.
The reward decided by the Jones and Marsh families is the admission of Jeff and Melly to their school's Blue Light Disco, seeing the enthusiastic encouragement of their budding romance as the ultimate treat. The Hall parents supply their children with alcohol and cigarettes, the eldest Jones children receive their first car, and Bec is permitted to begin birth control.
The night of the dance arrives, and Jeff and Melly find themselves dressed up and pressured to drink to an uncomfortable degree. At the dance, the Hall boys pass around alcohol, and Bec hands out doses of her medication to eager girls. Devastated with the mood of the night, Jeff and Melly leave early and return home after sharing a flask near Chips' body and overhearing the town authorities' plans to dispose of the whale via detonation. Arriving back at the Marsh house, they are pressured to have sex and instead choose to cuddle up like they did the night of the party and sleep, peacefully this time.
The families of Wyong Place reunite one last time to watch Chips' final sendoff, earning a front-row seat to the unforeseen repercussions of blowing up a large whale carcass. They, along with their homes, are covered in blood and rotten meat. While most beach-goers run screaming, Jeff and Melly find a moment of peace to dance and kiss in the rain of blood.
In a final scene taking place five years later, Rebecca and Rooster take their children on a vacation, only to find and return Tommy the tortoise to his former home in Wyong Place.