Captain Janeway participates in a mind meld with Tuvok, who relives his experiences on the U.S.S. Excelsior under the command of Captain Sulu at the time of Star Trek VI: The Undiscovered Country (1991).
Nearness to a class-17 nebula triggers a repressed memory in Tuvok, which can be a life-threatening condition for Vulcans. Janeway, as the closest thing to a trusted family member, agrees to mind-meld with Tuvok to ease him through it safely. Together they travel back in memory to when Tuvok served under Captain Sulu aboard the U.S.S. Excelsior.—statmanjeff