<Tr> <Th> Affiliation </Th> <Td> United Federation of Planets Borg Collective Starfleet </Td> </Tr> <Tr> <Th> Posting </Th> <Td> Astrometrics USS Voyager </Td> </Tr> <P> Seven of Nine (born Annika Hansen) is a fictional character who appears in seasons four through seven of the American science fiction television series Star Trek: Voyager . Portrayed by Jeri Ryan, she is a former Borg drone who joins the crew of the Federation starship Voyager . Her full Borg designation is Seven of Nine, Tertiary Adjunct of Unimatrix Zero One . The character Seven of Nine arrived just as the character Kes was leaving, and was intended to introduce a foil to Captain Kathryn Janeway in a similar manner as Spock in Star Trek: The Original Series . </P> <P> Seven of Nine was played by Jeri Ryan for four Voyager seasons . The character was a part of the last four seasons which concluded in 2001 with its seventh season, and Seven was featured in many episodes despite coming later to the series . Seven was introduced in the second part of the episode "Scorpion", the first episode of the fourth season . The character continued to appear throughout the series until the final episode, "Endgame". Stories related to her relationships with Captain Janeway and The Doctor appeared throughout the series . </P>

When did 7 of 9 appear on voyager