In 1996, star athlete Calvin Joyner is being honored at his high school. Halfway through Calvin’s speech, Trevor Olson and a group of bullies throw a naked Robbie Wierdicht, who was showering, into the hall where the assembly is taking place, embarrassing him. Only Calvin and his girlfriend, Maggie Johnson, are sympathetic towards Wierdicht.
Twenty years later, Calvin is married to Maggie and works as a forensic accountant but is dissatisfied with his career. Maggie suggests they see a therapist to salvage their deteriorating marriage. At work, Calvin receives a friend request on Facebook from a man named Bob Stone, who reveals that he is Wierdicht and requests that they meet. Calvin is shocked to see that Wierdicht has transformed into a muscular, confident man. Stone asks Calvin to review a few accounting records. Calvin deciphers the records as multi-million dollar transactions from an auction, with the final payment set to be made the following day. Stone avoids Calvin’s questions and spends the night on his couch.
The next morning, a group of CIA agents led by Pamela Harris arrive at Calvin’s house in search of Stone, who escapes. Harris tells Joyner that Stone is a dangerous rogue agent who intends to sell satellite codes to the highest bidder. Soon after, Stone abducts Calvin and explains that he is trying to stop a criminal known as the Black Badger from selling the codes but needs Calvin’s skills to find the coordinates of the deal’s location. After an attack by a bounty hunter, Calvin flees and calls Maggie, telling her to meet him at the marriage counselor’s office. Harris intercepts him and tells him that Stone murdered his partner Phil Stanton and is the Black Badger himself. She warns him to refrain from telling Maggie and gives him a device to alert them to Stone’s location. Calvin then arrives for marriage counseling, where he finds Stone posing as the counselor.
Stone convinces Calvin to help him, and Calvin sets up a meeting with Olsen, who is able to track the offshore account for the auction, so they can get the deal’s location. Harris calls Calvin and threatens to arrest Maggie if he fails to help them detain Stone. Calvin is forced to betray Stone, and the CIA arrests him. As Harris tortures Stone to get him to confess, Calvin decides to help Stone escape. Calvin deduces that the deal is happening in Boston and helps Stone steal a plane. At an underground parking garage, where the deal is assumed to be taking place, Stone enters alone, while Calvin sees Harris entering a short while later. He mistakenly assumes that she is the Black Badger and runs after her, but finds Stone meeting with the buyer and claiming to be the Black Badger. Stone shoots Joyner, grazing his neck, to keep him safe.
Stanton arrives, revealing that he is alive, and claims he is the real Black Badger. The buyer attempts to retrieve codes from both Stone and Stanton, but the CIA arrives and a shootout begins, while Calvin grabs both codes and runs outside. He encounters Stone and Stanton, who engage in combat. Unable to decide who is the criminal, Calvin randomly shoots Stone, but Stanton confesses that he is the Black Badger and that Stone is innocent. Calvin causes a distraction that allows Stone to rip Stanton’s throat out, killing him. The two deliver the codes to Harris, who then drops them off at their high school reunion, where Calvin reconciles with Maggie. Stone is announced as the Homecoming King, with Calvin revealing to Maggie that he hacked the voting system to ensure Stone’s win. Olsen attempts to bully Stone a third time, but Stone knocks him out. As Stone delivers his speech, he relives his most embarrassing high-school moment and takes off all his clothes confidently. He walks off stage to unite with his high-school crush Darla Mcguavian.
Before the ending credits, Maggie is pregnant and Calvin has joined the CIA. As a gift for his first day on the job, Stone gives Calvin back his varsity jacket from high school, which Calvin had given to him after the senior assembly prank.