6. The Middle-earth Paradigm -

: Or as Raj points out, looking suspiciously like Peter Pan. The Social Collision

: Wearing a skin-tight bodysuit with vertical black-and-white lines, Sheldon spends the evening making a "Neeeeooooowwwww" sound to represent a shifting frequency wave, a joke that remains entirely over the heads of the other partygoers. 6. The Middle-Earth Paradigm

The episode centers on a Halloween party hosted by Penny, which marks the first time Leonard and his friends attempt to integrate into her social circle. The Costume Crisis : Or as Raj points out, looking suspiciously like Peter Pan

The comedy begins long before the party starts, as the four friends realize they have all independently decided to attend as . After a brief "debate" (and several costume changes), they settle on a more diverse—though no less eccentric—lineup: : Or as Raj points out