Charlie resides in Florida with his materialistic wife, Nikki, and her two unpleasant twin sons from her ex-husband, Ted-O. Employed as a bank manager in a supermarket, Charlie's life feels mundane and troubled, especially since Nikki is unfaithful, engaging in an affair with Ted-O. Everything changes when Charlie reunites with his high school friend, Max, at a class reunion. The two decide to spend a weekend on a yacht rented by Max, rekindling some youthful spirits in Charlie.
However, things take a drastic turn when Max stages an explosion on the yacht to fake their deaths. Upon awakening, Max reveals that he is not truly an FBI agent, but rather a coroner, allowing him to switch their identities with two unclaimed cadavers. Now, Charlie assumes the identity of Dr. Ronald P. Fishman, while Max becomes Butch Ryder. Initially shocked, Charlie gradually finds the idea of a fresh start appealing, especially after seeing the dismal attendance at his own funeral and observing Nikki's swift return to Ted-O, as well as his position at the bank being filled.
Max informs Charlie about a key discovered in Butch's body, which Charlie deduces leads to a safe deposit box in Puerto Rico. The duo travels there, uncovering a stash of cash and keys to a luxurious mansion complete with a Ferrari in Butch's safe deposit box. They transition to this new life, quickly forming a bond with their neighbors, Dawn and Joan, leading to a wild evening filled with unexpected pleasures. During this escapade, Dawn hints that the original occupants, Butch and Ronald, had hurriedly purchased the estate, suggesting they were fleeing from something.
As they settle into their new surroundings, they stumble upon a photo revealing that Ronald was married. Their investigation leads them back to the attacks from assassins, orchestrated by the mysterious The Gymnast. They narrowly escape, but not before Max confesses that he is not actually a coroner; he is a guidance counselor. Their quest soon takes them to Savannah, Georgia, where they confront Heather, Ronald's widow, and reveal the troubling circumstances surrounding Ronald's death and involvement with Butch in criminal activities.
Heather reveals alarming information about a recent burglary in Ronald's study, prompting their next move to infiltrate a biker bar, a place where Ronald and Butch were known to frequent. Here, they meet Dakota, who informs them about Butch's terminal cancer diagnosis and the desperate measures he undertook—including operating illegal clinical trials for Ronald's innovative cancer treatment. Tension escalates when Dakota falls victim to The Gymnast.
As Charlie grows closer to Heather, their journey leads them to Max's mother's home, where they find themselves entwined in Max's complications with his ex, Becca. The men discover that the recent home invasions were likely related to the sought-after cancer cure. In a heart-wrenching realization, Charlie uncovers that Max had been one of Ronald's patients needing the very treatment they hope to find.
Returning to confront Shecky, Ronald's financier, they learn that the secret formula is desired by Trojgaard, a large chemotherapy firm. The stakes rise when The Gymnast takes Max hostage, while Charlie realizes that the key to the cure lies within a Jenga app on Butch's tablet. As chaos erupts, Heather betrays them, revealing her guilt in the murder of both Ronald and Butch.
In a pivotal moment, a confrontation between Charlie, Max, and Heather unfolds. Just when Heather threatens them, Becca springs into action, allowing them to reclaim the tablet. However, an accident leads to its drowning, yet hope remains as Charlie reveals he backed up the crucial data on a USB drive. The government grants the men pardons in exchange for the cancer treatment, leading to a bizarre revenge that Charlie exacts on Nikki, Ted-O, and the twins.
In the end, Charlie, Max, Becca, along with their son and Max's mother, find solace as they return to the mansion in Puerto Rico, ready to embrace a new chapter in their lives after Max's miraculous recovery.
