The film opens with a Bible quote from Nahum 3:6: "I will cast abominable filth upon you, make you vile and make you a spectacle."The first thing shown is a bloody chimp wandering around a messy sitcom set. This will make sense later.Otis Haywood Sr. and his son, Otis Jr. (referred to as OJ), begin their day by taking care of the horses at their Hollywood ranch, Haywood's Hollywood Horses. In the background, a radio mentions the mysterious disappearance of two hikers. Soon, the electricity goes out and, after screams are heard from the sky, debris falls from the sky. A coin falls through Otis Sr.'s eye, killing him. OJ tries to get him to the hospital to no avail. Later, after arriving back at the ranch, OJ notices a key impaled into one of the horses.The opening credits are shown along with a green square, later zooming in to the first motion picture of a black man riding a horse.6 months after the event, OJ waits for his sister Emerald (referred to as Em) on a movie set where one of their horses, Lucky, is to be used for a commercial filmed by cinematographer Antlers Holst. Emerald soon arrives and helps explains the safety precautions of filming with Lucky, also mentioning that the black man on the horse in the first motion picture is her and OJ's great-great-great grandfather. However, the staff ignores them and disrespects the horse's boundaries, causing it to react violently. The Haywoods are fired from the project, with a VFX horse replacing Lucky instead.With the ranch struggling financially, the Haywoods go to meet Ricky "Jupe" Park, a former child actor who owns a Western-themed amusement park titled Jupiter's Claim, to sell Lucky to him - the 11th horse to be sold. During the meeting, Jupe recounts an SNL sketch based on a traumatizing event during his child acting career, when a chimp actor went berserk on the set of the sitcom Gordy's Home. Jupe offers to buy the Haywood ranch, and Em later encourages OJ to accept the deal.That night, Em recounts to OJ about how Otis Sr. promised Em that she would train her first horse named Jean Jacket, although the horse would later end up being used for a film, which ended up using another animal anyway. Em notices that Ghost, another horse of theirs, mysteriously ended up in the arena.Starting from this point, the film is divided into chapters, each title referring to the animals in the film. This chapter is titled GHOST.OJ goes to the arena and finds Ghost there. Suddenly, he notices something from far away - several lights and a voice playing on the speakers. The lights and the voice slowly turn off, and Ghost flees the arena. OJ finds Ghost fleeing from the ranch and disappearing while the other horses act violently in the ranch. As the electricity of the Haywood home turns off for a few seconds, OJ sees a flying saucer in the sky.OJ describes it as big and fast to Em. The two buy several cameras the next day at Fry's Electronics, seeking to be famous from the footage, where staff member Angel Torres explains to them that he'll help set up the cameras, theorizing that the Haywoods might be in a UFO hotspot. Later on, he visits the ranch to do so, describing his perspective on aliens in the process. Em leaves momentarily and returns with a stolen display horse from Jupiter's Claim, intending to use it as bait. Jupe later arrives at the ranch to question Em about the display horse, but she bluffs her way out of it. Jupe attempts to invite the Haywoods to an event, but his flyer is taken away by the wind. He then leaves.This chapter is titled CLOVER.That night, the cameras and the decoy horse are set up. OJ notices that someone let another horse, Clover, out. He then encounters what seems to be multiple aliens. When one of them sneaks behind OJ, he punches it in the face - only to find out it's a child. The aliens are revealed to be Jupe's children, taunting him for stealing their decoy horse.Later, OJ goes to find Clover, but the UFO arrives and sucks up the decoy horse, which gets stuck, causing Clover to run away. Angel, secretly watching their cameras at Fry's, tells Em that the UFO is in the clouds, and Em shouts at OJ to run. OJ manages to hide safely, but witnesses Clover getting sucked up too. They fail to get the footage they need, as a praying mantis had blocked the view of a camera that stayed online, not affected by the UFO. Em tells OJ that they need to leave, but he tells her that there's more to this than they think and persuades her to stay and go on with the plan.The next day, Angel arrives at the ranch again, explaining that he rewinded through their footage and found a cloud that never moves, which might be the UFO's hiding place. Em contacts Antlers and tries to get him to join them, but he declines, claiming that they'd never wake up from this dream of being famous. OJ wonders if the UFO isn't a ship.This chapter is titled GORDY.The year is 1998. Young Jupe and his fellow actors act in an episode for the sitcom Gordy's Home titled Gordy's Birthday. During a scene where balloons are released in the room, the balloons start popping, shocking the chimp playing Gordy, who starts to go wild and attacks the human stars. Jupe hides under a table, sees a shoe standing up on its own (which he would later put on display in the future), and watches as fellow co-stars Mary Jo Elliot and Tom Bogan get attacked by the chimp, who calms down after finishing the attacks. The chimp notices Jupe and approaches him, using sign language to ask what happened to the family. The chimp reaches out his fist for the duo's iconic fist bump, but before their fists can touch, the chimp is shot dead.Back in the present, Jupe thinks about the massacre. His wife, Amber, motivates him to prepare for an upcoming event, and helps him recite his lines.This chapter is titled LUCKY.While Angel sets up tarps for a coming storm, OJ finds Jupe's flyer promoting the Star Lasso Experience. Deducing that this might involve Lucky, he heads to Jupiter's Claim to get Lucky back.Meanwhile, the Star Lasso Experience is starting. Jupe tells the audience about a night where he witnessed the UFO, and promises that they will leave different after witnessing a spectacle. The UFO arrives early. Jupe reveals a glass box that contains Lucky, meant to be sucked up for the show. Lucky refuses to walk out of the box, and the UFO appears above the audience, which include Mary Jo Elliot, whose face has been disfigured from the Gordy incident. The camera focuses on Jupe's shocked expression as the shadows behind him depict the audience being sucked up by the UFO.The inside of the UFO is shown, and it is revealed to be an alien itself, with the green square from the opening credits being its eye. Thus, Jupe, his family, and the audience are digested by the alien, while screams and the crunching of bones are heard in the background.OJ arrives at the empty Jupiter's Claim and finds Lucky, before the alien returns to try to suck him up and he gets knocked out by the bleachers of the arena. He wakes up at night and finds Lucky intact, before loading the horse into his truck and driving towards the ranch. He calls Em and warns her that the UFO is actually a predatory alien who sees the ranch and the area surrounding it as its territory, while Angel, about to leave the ranch, is forced to seek refuge in the house. The alien arrives above the Haywood house and vomits blood and debris, to Em and Angel's horror. OJ arrives at the house but his truck is shut down before he can reach it, and the alien goes above the truck and spits out the decoy horse.The next morning, OJ gets Em and Angel to flee in Angel's truck, and the alien arrives again. Recalling the earlier incident with Lucky on the commercial set, OJ doesn't look at the alien and manages to survive the encounter. The group gets away successfully and goes to Angel's apartment. That night, while eating dinner, OJ explains that the alien feels challenged when people look at it and then eats them. Meanwhile, Antlers listens to a news report about the disappearance of the Star Lasso Experience's audience and decides to join OJ, Em, and Angel.The next day, he visits their house and the group begins to plan. Antlers will bring a hand-cranked camera that won't be deactivated by the alien, now called Jean Jacket, the group will use tube man props to deduce where the alien is, Em will watch the area using cameras, and OJ will bait Jean Jacket.This chapter is titled JEAN JACKET.The next day comes and the plan is set into motion. However, Ryder Muybridge, a TMZ reporter, trespasses on the area and falls off his motorbike when Jean Jacket deactivates it. OJ attempts to save Ryder but is forced to leave him to die when Jean Jacket arrives. OJ successfully baits the alien, helping Antlers to capture footage. However, Antlers decides that the world doesn't deserve the footage, and lets himself get killed by Jean Jacket, destroying the footage in the process.After Em and Angel survive their encounters with Jean Jacket, it starts to unfold into a huge jellyfish-like form. After Em and OJ salute each other, the former uses Ryder's motorbike to drive towards Jupiter's Claim while the latter baits Jean Jacket away. Once reaching Jupiter's Claim, Em untethers the park's giant balloon mascot and uses the Winkin' Well, an attraction that uses an analog camera, to capture a photo of Jean Jacket as it eats the balloon mascot. The balloon and Jean Jacket explode, and after screaming in triumph, Em rests near the Winkin' Well.As reporters arrive, Em stands up, closes her eyes, and opens them again to see OJ riding Lucky, appearing from the fog. The film ends with a shot of the photograph of Jean Jacket.