Seven of Nine and the crew discover a virtual world in the Borg collective.
Seven of Nine discovers that she once visited Unimatrix Zero, a forest realm that a small number of Borg drones with a rare genetic trait reach in their minds while they regenerate. There they live as individuals, and among them is Axum, a man Seven once loved but has forgotten. The Borg Queen sees the place as a sickness and is destroying the drones who go there.
Through a mind meld with Tuvok, Janeway enters Unimatrix Zero with Seven and offers to help. The plan is to release a nanovirus that lets the drones keep their memories of the realm once they wake, so they can resist the Collective. The Queen offers Janeway transwarp technology to stay out of it, but Janeway refuses. She, Tuvok and Torres board a Borg cube and are captured and assimilated, as Voyager pulls away. The sixth-season finale ends on that cliffhanger.