Leonard and Sheldon's friendship is put to the test when Leonard wants to present a paper they co-authored at a physics convention, but Sheldon doesn't.
Leonard lies to Penny so he and Sheldon can get out of watching her perform, but Sheldon believes that the lie has too many loose ends, so he comes up with a new, unnecessarily complex one to replace it.
Sheldon decides to give up his work and focus on other tasks when a 15-year-old prodigy joins the university, so the other guys come up with a plan to get rid of him.
Sheldon becomes so intent on demonstrating his intellectual superiority over the other guys that they kick him off the Physics Bowl team and replace him with his nemesis, Leslie.
Penny gets mad at the guys when their full scale model of a time machine causes her to miss work, which prompts Leonard to give up all of his nerd memorabilia.