In the 1960s, Seo Chang-dae, a man harboring political aspirations while temporarily managing a pharmacy, captures the attention of the ambitious politician Kim Woon-beom. Recognizing Seo’s drive and inventive mindset, Kim decides to bring him on board as a political aide. Seo quickly establishes himself as a sharp strategist, aiding Kim in securing a National Assembly seat in Mokpo, despite facing significant government interference and bribery efforts. After this victory, government officials approach Seo in an attempt to recruit him, but he firmly declines their offers.
As the New Democratic Party gears up for the forthcoming presidential election, Seo encourages Kim to confront the party establishment and seek the nomination. Kim enters a competitive race against the youthful Kim Young-ho, who champions a movement termed the "40s generation" that opposes party leader Kang In-san. Rather than leaning on established factions, Seo orchestrates an approach whereby Kim's campaign directly engages delegates nationwide. When Kang unites with Kim Young-ho and Lee Han-sang, Seo devises a tactical plan to target Lee, leveraging his political ambitions to fracture their alliance. Eventually, he persuades Lee to support Kim by offering him the coveted position of party chairman. In a dramatic turn, Kim triumphs over Kim Young-ho in the runoff and secures his position as the opposition party's presidential candidate, with Seo joining his campaign team.
During the intense campaign season, Kim faces backlash over his commitment to abolishing the reserve forces. In a bold move, Seo suggests staging a terrorist attack to cultivate public sympathy; however, Kim refrains from this strategy, cautioning that Seo lacks the requisite readiness for the political arena. Shortly thereafter, Kim's home is bombed, leading to Seo's arrest. Despite his eventual release, Kim requests that Seo withdraw from any official campaign activities. The ensuing confrontation reveals Seo's belief that political power is a tool to manipulate the masses, a perspective Kim adamantly opposes, emphasizing that politics should adhere to democratic ideals. When Kim questions Seo about his involvement in the bombing, Seo sorrowfully confesses, leading to the dissolution of their partnership.
With a new path ahead, Seo is recruited by Director Lee, transitioning into government work where he exploits regional differences, particularly historical rivalries between the Silla and Baekje regions, transforming the election into a battle of regional loyalties. As divisiveness escalates within the campaign, Seo becomes increasingly disillusioned by the consequences of his actions. Ultimately, Kim suffers defeat in the presidential election, prompting Seo to exit the political scene. It is later uncovered that Lee orchestrated the bombing of Kim's home to drive a wedge between Kim and Seo, subtly steering Seo toward the government’s agenda, even as he continues to refute involvement.
Years later, fate brings Kim and Seo together once more, allowing them to reflect on their political journeys and the decisions that shaped their careers. Their conversation underscores contrasting views on politics and the methodologies for achieving political change. The film culminates in revealing that South Korea successfully executed its first peaceful transfer of power in 1997, concluding with the poignant reflection that Seo Chang-dae played no part in this pivotal moment.
