Suppose Anya (out of Buffy) met Jack (out of Doctor Who), and somehow ended up being very fond of him for some reason. Suppose further that Jack somehow got himself killed, and Anya got very upset about it and wreaked some terrible vengeance upon whoever was responsible.
And then Captain Jack comes back to life. D'oh! What an embarrassment. And this sort of thing just keeps happening.
Eventually Anya ends up with a long list of people she's wronged with premature vengeance. And she decides she needs to work her way down the list to make amends.
I call it "My name is Anya".