Perfect Cell Saga is the ninth saga in the Dragon Ball Z series. The manga volume that it is made up of is "The Room Of Spirit And Time". The saga is about Semi-Perfect Cell continuing his quest to reach his Perfect Form. It also features the ascension of the four Saiyans (Goku, Vegeta, Gohan and Future Trunks) while they try to come up with ways to defeat the growing android threat. It occurs between the Imperfect Cell Saga and the Cell Games Saga.