(If you missed Act I, you can see it here.)
Penny: Sometimes people are layered like that. There's something totally different underneath than what's on the surface.
Billy Horrible: And sometimes there's a third, even deeper level, and that one is the same as the top surface one.
Penny: Huh?
Billy Horrible: Like with pie.
- Dr. Horrible's Sing-Along Blog, Act II
