Leonard buys a replica time machine online believing it to be a miniature... though it turns out to be full-sized. As the boys move it into the apartment they accidentally make Penny late for work
causing her to lash out at Leonard for his nerdy ways. Upset, Leonard decides to get rid of all his 'nerdmabelia' and the guys try to convince him not to (or sell it to them, whichever). In the end
Sheldon confronts Penny about her own love of childish things (Hello Kitty, Beanie Babies, etc) and she apologizes to Leonard. However she has a new boyfriend named Mike, and once Leonard finds this
out he reverts to his old ways.