A veteran Secret Service agent, haunted by his failure to protect President John F. Kennedy, leads a solitary life dedicated to his job. When the president is set to visit Los Angeles, the agent is resolute in ensuring history does not repeat itself. However, his journey towards redemption is challenged when he becomes embroiled in a deadly game of cat-and-mouse with a disgruntled and meticulous assassin. This assassin, nursing a deep-seated grudge against the American government, plans to make a name for himself by killing the current president.

The agent's attempts to track down the would-be killer are met with skepticism by his younger colleagues, who see him as a relic of a bygone era. Despite the iterated skepticism, he perseveres, driven by a strong sense of duty and the ghosts of his past. The hunt intensifies as the assassin proves to be an intellectual match for the agent, engaging him in psychological warfare. This dangerous interaction reveals the assassin’s detailed knowledge of the Secret Service and his relentless dedication to his cause. As the planned presidential visit draws nearer, the stakes rise, complicating the agent's mission to avert another national tragedy and finally lay his unresolved burdens to rest.