With Sheldon rattled and impossible to be around after meeting Dennis, a 15-year-old physicist who's smarter than he, the rest of the guys search for a way to eliminate the threat.
Leonard and Sheldon each lie to avoid hearing Penny sing in a production of Rent. However, Sheldon's lie becomes a bit too complicated for its own good.
Sheldon's getting fired forces him to explore what life has to offer outside physics, leaving Leonard to take drastic action to snap his friend out of his funk.
Brilliant physicist roommates Leonard and Sheldon meet their new neighbor Penny, who begins showing them that as much as they know about science, they know little about actual living.