An aspiring supervillain discovers that taking over the world is no easy task while attempting to get accepted into the Evil League of Evil and summoning the courage to finally make conversation with his laundromat crush. Better known to the world as "Dr. Horrible," Billy (Neil Patrick Harris) has big plans for world domination, though they never seem to pan out. If Billy could just accomplish his duel goals of gaining entry into the most exclusive supervillain club in the world and finally break the ice with pretty Penny (Felicia Day), perhaps people would start taking him seriously as a diabolical mad genius. The only thing preventing Billy from realizing his one true destiny as a destroyer of worlds is his arch nemesis Captain Hammer (Nathan Fillion), an irritating do-gooder who thwarts him at every turn, and seems to have an eye on Penny as well. But Billy's got a plan, and if it all goes right he'll soon be sitting pretty in the E.L.E. with Penny by his side, and rid of pesky Captain Hammer once and for all.