The latest season of Prime Video's "Reacher" kicks off with a jarring encounter on a Philadelphia street. Jack Reacher, embodying his solitary nature, witnesses a woman, later identified as Anna Merrick, commit suicide in a subway car. His military training and instincts immediately identify her distress, but despite his attempts to intervene, she takes her own life.
This incident draws Reacher into a complex investigation. He is questioned by detectives Tamara Green and Shaun Docherty, who are accustomed to Reacher's unconventional lifestyle – lacking ID, a permanent address, or any possessions beyond his passport. Reacher expresses a desire to help Anna, even posthumously, and his inquiry is further complicated by the arrival of federal agents. These agents suspect Anna may have passed Reacher a flash drive containing sensitive information.
Reacher's path leads him to Anna's brother, Jacob Merrick, a police officer in New Jersey. He learns that Anna was involved in something significant enough to alarm the federal government, a situation so dire that she saw no escape. The situation escalates when Reacher is confronted by thugs demanding the same flash drive, an encounter that leads to street brawls.
Through these confrontations, Reacher identifies Lila Hoth, who reveals the flash drive holds information about John Sampson, a former Delta Force officer and a North Carolina congressman with presidential ambitions. The sensitive data reportedly concerns Sampson's alleged paternity of Lila during a top-secret mission in Indonesia in the 1990s.
The investigation takes Reacher to the Philadelphia Public Library, ostensibly for records related to Sampson's military career, but also serving as a staging ground for another confrontation. He is attacked by an assailant seeking the flash drive, whom Reacher incapacitates using the library's archive stacks.
The episode concludes with Reacher being targeted by a new group, seemingly government operatives with advanced tactics. They subdue him with tranquilizer darts, leaving him captured and held in a cell, setting the stage for further developments in the unfolding conspiracy.