Bleach Volume 28

Using their new fighting skills, Uryū and Chad easily defeat Demōra and Iceringer before they and Ichigo escape the collapsing building. Upon seeing Las Noches, the castle Aizen is located at, they begin running across the desert of Hueco Mundo for are impeded by the various natural hazards. In the desert, they encounter three hollows in pursuit of small child, and go to her defense. But they learn the child is an arrancar named Nel and the hollows are her mutually adopted brothers Pesche Guatiche and Dondochakka Bilstin and their pet Bawabawa. Nel and her family, despite initially distrustful toward Ichigo, guide him to Las Noches before Rukia and Renji arrive to save them from the sand-based hollow Runuganga. After breaking into Las Noches and finding themselves at a five-way fork, Ichigo's group splits up and each takes one path. When Nel chases after Ichigo, Pesche and Dondochakka forget the direction she took and travel down different paths. Ichigo, Uryū, and Chad soon each encounter a Privaron Espada, Espada who have been demoted in favor of stronger replacements.

Baron's Lecture Full-Course
Contains chapters 243 - 251.