Seven of Nine, having recently been liberated from the Borg collective, is starting the process of learning to be a human again. She begins having flashbacks (or hallucinations) involving Borg and, strangely, a large black bird. The Doctor diagnoses her with post-traumatic stress disorder. He decides to help her move forward by starting her on a diet of real food; now that she has been relieved of her Borg implants she'll need to take in nutrients. Neelix prepares a first meal for her to start on, and coaches her on the basics of chewing and swallowing. Suddenly she is struck by another vision, and a Borg implant grows from her skin. She jumps up and threatens to assimilate Neelix.
Captain Janeway is right in the middle of negotiating passage through space owned by the B'omar. Her duty is made harder when Seven steals a shuttle and leaves Voyager with it, trespassing into B'omar space.
The Doctor figures that Seven's Borg nanoprobes have reactivated and are taking over her body and mind again. The crew cannot recover her because the B'omar won't allow Voyager into their territory, but Tuvok and Tom Paris are able to covertly cross B'omar security lines in a shuttle and go after Seven. Tuvok transports to her shuttle but Seven is able to subdue him. She explains that she is following a Borg homing beacon. When Tuvok tells her there are no Borg ships anywhere in the vicinity, she tells him he's wrong and steers the shuttle to a moon.
On Voyager, Janeway is trying to figure out what caused Seven to leave. After reviewing Seven's logs, she reads something about a raven. She orders Voyager to scan for any Federation ship other than their shuttles and to set course for B'omar space.
On the moon's surface they find no Borg, only the wreckage of an old Federation ship. It shows signs of Borg invasion and partial assimilation. Seven feels that the ship is familiar to her; very familiar. There is a bit of Borg machinery still active on board, which is what caused Seven's homing instinct to reactivate. As she looks around the ship, the memories hit her hard. This is her parents' ship, the Raven. It was taken by the Borg almost twenty years ago, when Seven was a little girl named Annika Hansen. She and her parents were assimilated on this very spot. Suddenly, the B'omar attack though the crew is able to escape and Voyager disables the B'omar ships before fleeing.
Later, Janeway mentions the existence of records on Seven's parents, and Seven decides that one day she will read them.