In 2374 Seven of Nine was cut off from the Borg Collective and remained aboard Voyager, beginning her slow return to life as an individual.
Seven of Nine had been assimilated as a child named Annika Hansen. After the war with Species 8472 she was severed from the Collective in 2374, and the Doctor removed most of her Borg implants. She angrily demanded to return to the Borg, but Janeway refused.
The same year, Kes's growing mental powers forced her to leave the ship, and before going she pushed Voyager about 10,000 light-years closer to home. Seven took her place as a crew member and began to learn about life as a human.