Trouble is brewing in Las Noches, Aizen's palace in the Hollow realm, Hueco Mundo. One of the Arrancars, Patras, rebels against Aizen and tries to steal the Hogyoku. Ulquiorra realizes what Patras is up to, but he is defeated when he is caught off-guard by Menis and Aldegor, who assist Patros in his rebellion. Upon obtaining the Hogyoku, the three go to the World of the Living, where they head to Urahara's shop in order to find Kisuke Urahara, the creator of the Hogyoku.
Bleach Collection 09 (Eps 134-145)
Civil War in Hueco Mundo