Captain Picard is disturbed to learn that the legendary Vulcan, Mr. Spock, has gone on an unauthorized mission to the planet Romulus. He immediately travels to Vulcan to speak with Spock's father Sarek, a close friend with whom he shared a mind meld the year before. Sarek's wife, Perrin, informs Picard that her husband is gravely ill, and confides to Picard the details of the strained relationship between Spock and his father. Despite Sarek's illness, Picard is able to see him, and the Vulcan tells Picard that his son may be in touch with the Romulan senator Pardek. He also asks Picard to convey his love to his son. Back on board the U.S.S. Enterprise, Riker and La Forge inspect several metal fragments, identified as Vulcan, recovered from a downed Ferengi ship. When the Vulcans claim to know nothing about the materials, Riker and Geordi assume the Ferengi have stolen them.
Upon his return to the Enterprise, Picard summons the help of the Klingons in hopes of receiving an undetectable ship to use to travel to Romulus. After several days, Picard finally reaches Gowron, who provides the vessel after a great deal of prodding. Meanwhile, covert reports from Romulus confirm Spock's meeting with Senator Pardek, who Data learns has been an advocate for peace, and reunification of the Vulcan and Romulan states, for many decades.
Disguised as Romulans, Picard and Data make their way toward the planet in the Klingon ship. At the same time, Riker and Troi work together to find out how the metal material, now identified as a disassembled Vulcan deflector array, ended up in the hands of the Ferengi.
During a difficult night aboard the Klingon ship, Picard is informed that Sarek has died. While investigating the mysterious Vulcan deflector array, the Enterprise encounters an unidentified alien warship. When the ship refuses to answer Riker's hails and prepares to attack, Riker orders Worf to fire a warning shot. Although the firepower used is small, the hostile ship explodes into space.
Picard and Data transport down to Romulus where disguised, they stop at a cafe across from Senator Pardek's office. They see Pardek and begin to move toward him when suddenly they are kidnapped by several Romulan soldiers. Later, however, they are approached by Senator Pardek, who explains that he had them kidnapped for their own protection. As Picard briefs the Senator on the reasons behind his mission, Spock suddenly appears before him.