Power Rangers Zeo begins immediately after the events of Mighty Morphin Alien Rangers, where Tommy and the other Rangers (Adam, Rocky, Tanya, Katherine and Billy) witness the destruction of the Command Center. After recovering, the powerless Rangers discover the Zeo Crystal intact in the rubble—apparently dropped by Goldar and Rito Revolto. The Crystal guides them to a portal, which takes them deep underground to the Power Chamber where they find Zordon and Alpha 5 waiting for them. The Mighty Morphin Power Rangers become the Zeo Rangers, a new team of Rangers powered by the Zeo Crystal. The four remaining Mighty Morphin Rangers, Tommy, Adam, Rocky and Kat become Zeo Ranger V — Red, Zeo Ranger IV — Green, Zeo Ranger III — Blue and Zeo Ranger I — Pink respectively and Tanya Sloan joins the team as Zeo Ranger II — Yellow, while Billy chooses to become their technical advisor rather than continuing as a Ranger.