Growing the Beard: When Bizenghast began, the first volume focused on the fact that Dinah was able to see and interact with the numerous ghosts that haunt her home. As the books progressed this aspect was near dropped entirely save for Dinah's interaction with the ghost of Addie Clark. On a wider scale, the series gradually moved away from the "save tortured souls" as the main plot and began to focus on Dinah's growth as a person and the overall dark history behind Bizenghast. The change is lampshaded by Edaniel in the sixth book:
Edaniel: It used to be so simple, huh? Solve riddle A, clear out vault B, learn valuable lesson C.