Nobody insults Giles' books! Well, except for mysterious lady Watchers... The explore this episode all about secrets; Angel, Xillow, the glove of Minnegan, a few of them get revealed (see what I did there) and the drama that lies therein. Giles' emotional reaction to the Angel news, and Xander acts as you would expect him to are a big conversation point, along with "who is Gwendolyn Post?"
