Following the destruction of the Enterprise-D, Riker transferred to its successor, the Enterprise-E, with Picard, and continued to serve as first officer until 2379, helping to defend Earth against the Borg, prevent the illegal relocation of the Ba'ku and destroy the Reman warbird Scimitar. Shortly before the Scimitar's destruction, Riker married his off-and-on lover, Deanna Troi, who thereafter transferred to the Titan with him to serve as the vessel's counsellor and chief diplomatic officer. Commander Christine Vale is a human female and executive officer of the starship Titan. Vale previously served as the Enterprise-E's chief tactical officer. Coming from a long line of peace officers on Izar, Commander Vale's family was gravely disappointed in her choice to join Starfleet. Commander Deanna Troi is a half-Human, half-Betazoid female. The wife of Captain Riker, Troi serves as the vessel's chief diplomatic officer as well as ship's counselor, a position she previously held on both the Enterprises D and E under Captain Picard, to whom she often served as an advisor. Speaking during Riker and Troi's wedding, Picard noted that Troi had been his "guide and [his] conscience" in her years on the Enterprises. Despite being only half Betazoid, Troi is a capable empath and has been shown to communicate telepathically with other Betazoids, specifically her mother, Lwaxana Troi. According to the non-canon novel, Imzadi, Troi joined Starfleet following a romantic relationship with Will Riker. (This is alluded to in "Encounter at Farpoint".) Commander Tuvok is a Vulcan male. Tuvok shares the cold and logical nature associated with his people. His first Starfleet assignment was aboard the USS Excelsior under Captain Hikaru Sulu, most famously during the events of Star Trek VI: The Undiscovered Country. During his service Tuvok became disenchanted with non-Vulcans and resigned from Starfleet, only to join again decades later, where he eventually settled aboard the USS Voyager under Captain Kathryn Janeway. In 2371, Tuvok was on an undercover mission infiltrating the Maquis when he became trapped in the Delta Quadrant. He was later re-united with Voyager and served as the vessel's head of security until its return home. Following his return, Tuvok worked for Starfleet Intelligence within Romulan space at the time of the Shinzon uprising, and was later rescued from imprisonment by the Titan crew, which he joined when their previous tactical officer became comatose as a result of battle. After Titan was briefly lost in the Smaller