The film begins with a gripping scene where Bobby, portrayed by Jacob Elordi, is seen driving through the desert, carrying a severely injured man in his vehicle, who may even be dead. As he casually talks about the Hoover Dam, he abruptly pulls over and disposes of the body, setting a dark tone for the narrative.
Several weeks earlier, in the summer of 1964, we meet Jim, played by Zachary Quinto, whose car breaks down on Route 66 in Death Valley, California. He takes his vehicle to a mechanic operated by Willard, portrayed by Christopher Guyton, who informs Jim that the repairs will come at a hefty price and casually mentions Jim's cargo. While Jim speaks on the phone with his wife and business partner, Esther, played by Denise Sante, he contemplates visiting his brother-in-law, Saul, played by Patrick J. Adams, but is scolded by Esther, who reminds him that she meticulously planned their business strategy and urges him not to stray from it.
During this call, Jim notices Bobby attempting to hitch a ride to Michigan, who also has a tense exchange with Willard. Jim offers Bobby a ride after he learns that Bobby's car had also broken down, which Bobby eagerly accepts. On the journey, Bobby shares that he is heading to Michigan for a homecoming with his girlfriend, while Jim reveals he is delayed on his trip to Chicago and might need help in driving to make up for lost time. However, the atmosphere shifts when Bobby reacts defensively after Jim pries into his Air Force discharge.
Their dynamic changes as Jim reveals he is transporting a chimpanzee named Spanky, played by Phoenix Notary, to Chicago. Initially put off, Bobby soon recognizes Spanky from various talk shows and chooses to remain with Jim.
They stop for the night at a motel in Albuquerque, New Mexico. Jim suggests a two-bed room, but Bobby opts to sleep in the car, asserting that he can take care of Spanky. The motel proprietor, Hank, played by Troy Evans, warns them about local dangers while trying to sell a knife, but Jim remains focused on securing a room.
The following morning, tensions escalate when Bobby holds Jim at gunpoint after a confrontation, stealing his wallet and ring. In a series of flashbacks, we learn that Bobby committed murder in the past and is a deeply troubled character. Despite the threats, Jim tries to reassure Bobby while attempting to figure out a way to deal with his mounting issues.
As they continue their road trip, Jim suggests taking a detour to visit Saul, who he discovers to be a Catholic priest and his brother-in-law. The meeting reveals the strained financial situation Jim faces due to the cancellation of Spanky's contracts and his increasing desperation for money. Saul belittles Jim, but tensions explode when Bobby accuses Jim of using him only as muscle.
When they find themselves in Tulsa, Oklahoma, Bobby expresses a desire to go dancing, seeking to create a connection with potential partners. Jim feigns support, but he feels increasingly uneasy with Bobby's violent methods. Despite Jim’s attempts to find work for Spanky, things take a bleak turn as Bobby's erratic behavior comes to light.
As the narrative unfolds, the two characters undergo significant changes, with Bobby often revealing his violent tendencies and Jim caught in a complicated web of lies and dangers. Eventually, they arrive in Chicago, leading to a tense confrontation over Bobby's gun that culminates in a chaotic climax between the characters.
By the film’s conclusion, Jim manages to find a new home for Spanky while Bobby returns to his old life of crime, resulting in his arrest. Jim and Spanky, however, manage to emerge from the ordeal, navigating their careers with some success.
In a powerful narration that wraps up the story, it is revealed that Bobby never reached his intended destination, instead falling back into his violent past and ultimately facing the consequences of his actions. Meanwhile, Jim and Spanky find a semblance of peace after their tumultuous journey together.
