The Nature of Vengeance

Truth be told, Willow Rosenberg is not Anya's favorite person. And Anya is well aware the sentiment is mutual. Add to that the fact that Willow and Oz's relationship seems so solid and, well... Willow's the last person Anya would have expected to come to her for help getting vengeance, but apparently it's just one of those days. (Season 4 AU - Part 4 of a series)