Initial Vector was written by Greg Rucka and released in 2005. It is set six months after the events of the game and portrays Joanna as an ex-bounty hunter drawn into the Carrington Institute's battle with dataDyne through her own vendetta against the big corporations. Since Rucka could not play Perfect Dark Zero while he was writing Initial Vector, the novel is self-contained and does not give away much of the game's story. The novel also develops the character of Cassandra De Vries from the Nintendo 64 game to a greater degree. According to Rucka: "If you've played the first game, you're going to get a huge treat, because a lot of stuff that happens in Perfect Dark, we set up in the novel".