After a 200-year-old medicine jar found on an off-shore shipwreck shatters in a teenage girl's palm, she is admitted to Princeton Plainsboro for symptoms closely linked to smallpox. When the Center for Disease Control's Dr. Dave Broda institutes a lockdown on the hospital and suspends House's team's ability to diagnose, Masters is skeptical about Broda's diagnosis and becomes convinced that the patient is suffering from a different disease. The girl's father soon experiences similar symptoms, and House is forced to make a precarious decision that puts his own life in jeopardy. Meanwhile, Wilson and Sam comfort a 6-year-old chemotherapy patient who prompts them to examine their relationship.