House and the team take on the case of a woman who collapsed in the middle of a cooking class, and they soon learn she is a highly-renowned cancer researcher who recently gave up her entire career in order to pursue her own personal happiness. As the patient's condition continues to worsen, so does Thirteen's as she begins to suffer serious and life-threatening reactions to the experimental Huntington's Disease clinical trial.

The team encounters a teenage boy who collapsed from severe pelvic pain after playing basketball. Tests reveal the boy has genetic mosaicism, or both male and female DNA, and the boy's parents inform House and the team that the boy is unaware of his condition.