A jump splinters Voyager across alternate realities, and the crew visits the Mirror Universe.
The Protostar's proto-jump toward Voyager instead carries it through alternate realities, including one in which Janeway and Noum died rescuing Chakotay and another in which the living construct destroyed the Federation. The jump tears the already weakened fabric of the universe, splintering Voyager across several realities and affecting Gwyn. Rok-Tahk and Zero are stranded on a Voyager commanded by Tuvix, while the rest of the group, except Maj'el, who is accidentally left behind, lands in the Mirror Universe and faces evil counterparts of Janeway and Chakotay.
With the Loom threatening her own universe, the mirror Janeway reluctantly lets them use her ship to emit a pulse that closes the rift, and Chakotay is finally reunited with the real Janeway. The episode is a tour of Voyager-era alternatives, bringing back Tuvix from the Voyager episode of the same name, and it ends the long separation of Janeway and Chakotay. Erin McNamara wrote the episode.