Safe (S02E16)

Melinda, a rebellious teenage girl who's immunocompromised as a result of medications she's taking after a heart transplant, has a severe allergic reaction and goes into shock despite living in a "clean" room. House and the team step in to figure out exactly what caused the reaction, but end up playing referee between Melinda, her overprotective mother and her boyfriend. Melinda's heart condition worsens and she develops a paralysis that is slowly moving up her legs, and the team must rush to solve her case before the paralysis reaches her heart. Meanwhile, House and Wilson continue to work out the kinks in their new living arrangement. (iTunes)