It is Janeway's first day aboard the U.S.S. Voyager. Seven of Nine, disguised as an ensign, investigates a weapon on the ship and reports back to Captain Braxton, who now knows where the weapon was placed but still needs to know when. After Janeway is alerted to a chronoton flux, she almost discovers Seven of Nine, which would contaminate the timeline. Braxton beams Seven from Voyager just in time, but she is dead by the time she gets to his ship.
Braxton orders his men to go back in time and retrieve Seven before Voyager explodes. This is the third time they have tried to help Seven save her crew. On Voyager, temporal distortions are fracturing space-time throughout the ship, making people space-sick and causing bizarre paradoxes to occur. When Seven and Torres investigate, Seven's ocular implant detects a device emitting the distortions. Before they can take action, the hull begins to demolecularize. Janeway orders the crew to abandon ship as two men materialize and beam away Seven.
Seven is once again welcomed to the Federation timeship Relativity. It is 500 years in the future, and Braxton wants to solve the mystery of who planted the weapon. His crew has recruited Seven because of her ocular implant's ability to detect irregularities in space-time. Once they persuade her to help them, Seven is beamed to Voyager two years before she became part of the crew. The ship is under attack from the Kazon, and Braxton believes this is the time a saboteur boarded the vessel and planted the device. Seven is to find him and stop him at all costs.
Seven checks the ship and finds no sign of the weapon or the intruder. When Janeway detects a chronoton flux and remembers the same thing happening two years ago, she investigates and finds Seven, whom she recognizes from that first day on the ship. Over Braxton's objections, Seven explains her presence on Voyager and persuades Janeway to trust her seemingly implausible story. When they are suddenly alerted to an intruder, they find Braxton himself planting the weapon.
Suffering from temporal psychosis, this version of Braxton claims Janeway is responsible for his exile stemming from his time travel. He suddenly jumps to two years earlier, and Seven follows him. When he is trapped in a forcefield, Braxton jumps five years ahead. By this time, Seven is suffering from having made too many time jumps, and recruits herself in that time period to apprehend Braxton. Once Seven and Janeway catch him, Janeway must go back to an earlier period of Voyager's history to capture Braxton before he has a chance to place the weapon. Meanwhile, the original Braxton is arrested for "crimes he will commit" by his first officer, who takes command of the timeship and vows to clean up the contamination in the timeline to prevent any of it from happening in the first place. Seven is "reintegrated" and Janeway is urged to avoid time travel as the two are returned to Voyager and back to normal.