After receiving the news of the coup, Picard is approached by Admiral Kathryn Janeway and briefed on the situation. Janeway informs Picard that Shinzon is a genetic clone of Picard, created by the Romulans in an attempt to infiltrate and overthrow the Federation. Shinzon was abandoned on Remus as a child and grew up as a slave, leading a rebellion against the Romulan government and eventually rising to power.
Upon arriving on the Romulan homeworld, Picard and his crew discover that Shinzon has created a powerful warship, the Scimitar, which he plans to use to destroy Earth and the Federation. The Enterprise engages the Scimitar in a intense battle, ultimately leading to a showdown between Picard and Shinzon.
During their final confrontation, Picard learns that Shinzon's accelerated aging is causing his physical and mental deterioration. In a shocking twist, Shinzon reveals that he wishes to bond with Picard in order to utilize his superior genetic makeup to extend his own life. Picard ultimately kills Shinzon in self-defense, and the Scimitar is destroyed.
The film ends with the wedding of Riker and Troi, with Picard reflecting on the realization that he and Shinzon were both victims of a cruel experiment by the Romulan government.