Captain Jean-Luc Picard and the Enterprise-E crew find themselves on a diplomatic mission to initiate peace with the Romulans. Learning that the Romulans have undergone a political upheaval and their new Praetor, Shinzon, wants to discuss a peace treaty with the Federation, Picard and his crew must investigate the situation and determine Shinzon's sincerity. But they learn that not only is the new Praetor not a Romulan at all but a native of Romulus' sister planet Remus, they also find that he is a human replica of Picard, originally bio-engineered by the Romulans to be substituted for the captain as a weapon against the Federation. Now, Picard and his crew must determine if the Romulans truly desire a peace treaty, or if they have other plans in mind.