The film intertwines excerpts from Chuck's personal journals, public records, and recorded interviews to tell his story. In 1940, Chuck Barris, portrayed by Sam Rockwell, is a teenager in Philadelphia whose life revolves around his quest for promiscuity. Despite numerous attempts, he struggles with romantic conquests among various girls and women. A turning point comes in 1955 when he is inspired by a TV advertisement and relocates to Manhattan to become an NBC page, fueled by a desire for fame in the television industry.
Chuck's ambition leads him to deceit, as he fabricates details on his application for a management trainee position at NBC, where only five spots are available among 2000 applicants. He begins a relationship with fellow Page Georgia, leading to an unexpected pregnancy, which ultimately coincides with his dismissal from NBC—a revelation that she was merely late. Consequently, Chuck returns to Philadelphia and secures a job as Dick Clark's personal assistant on "American Bandstand" in 1961. Despite his burgeoning career, he finds himself entangled with Debbie, an ABC executive, played by Maggie Gyllenhaal, as he continues his pursuit of fame and fortune.
As his career takes off, Chuck composes the hit song "Palisades Park" and falls for Penny Pacino, a character brought to life by Drew Barrymore, who happens to be Debbie’s roommate. It is this romance that inspires Chuck's groundbreaking idea for a dating show. He convinces ABC to let him pitch the concept for "The Dating Game," resulting in a $7,500 budget to produce the pilot. However, the show initially faces rejection in favor of "Hootenanny."
After a bar fight leads to his dismissal, Chuck encounters CIA agent Jim Byrd, played by George Clooney, who recruits him as an assassin, convincing him with promises of adventure and the allure of Eastern European women. Chuck finds himself excelling in CIA training, particularly in sniper shooting. Upon his return from a mission in Mexico, he discovers a changed Penny, who has taken on a hippie lifestyle, just as "The Dating Game" is green-lit by ABC.
Despite initial shock from the network concerning the show's risqué content, Chuck defends its authentic spontaneity. He hires a coordinator to keep things within a PG-13 framework as the show skyrockets in popularity by 1967, securing a prime-time slot. As Jim suggests increasing prize money to cover Chuck's missions, he embarks on covert operations under the guise of his television career.
During a mission in Helsinki, he meets the alluring operative Patricia Watson but still finds success with "The Newlywed Game," leading him and Penny to move to Los Angeles. However, Chuck’s reluctance toward marriage complicates their relationship. His life parallels that of Teufelsdröckh from Thomas Carlyle's Sartor Resartus, a theme that recurs throughout the film.
In 1970, another assignment brings Chuck to West Berlin for a critical assassination. Captured by the KGB while infiltrating East Germany, he undergoes a harrowing experience before being exchanged for a Russian agent. By 1976, Chuck becomes a household name as the host of "The Gong Show" but faces critique over the declining quality of television programming. Tragedy strikes when Keeler—a colleague—mysteriously dies, leading Jim to warn Chuck of a mole within the agency.
As Chuck's television shows suffer from low ratings, his relationship with Penny deteriorates. In a surreal moment, Jim confronts Chuck, interpreting his past as indicative of a killer's profile, before met with an abrupt demise. This trauma haunts Chuck, culminating in a nervous breakdown on his show.
By 1981, when Penny finds him secluded in a New York hotel, she urges him to return and commit to their relationship. Faced with his secrets, Chuck ventures to Boston where he discovers Patricia's betrayal as the mole. The fallout leads him to violence, shaping him into a writer of his own story, Confessions of a Dangerous Mind, ultimately deciding to marry Penny. The film concludes with Chuck preparing for an interview about the adaptation of his life story, encapsulating the complexities of his dual existence as a television personality and covert assassin.
