House and the team encounter a teenager who collapsed during her high school Christmas program. They soon find the troubled teen dealt with more than her share of bullying at school, and as her condition continues to deteriorate, the team must delve deeper to get to the bottom of her mysterious illness. Foreman continues to work with Thirteen on the Huntington's disease drug trial, and their relationship progresses when he learns a valuable lesson from her. House gives a clinic patient an unbelievable holiday gift and keeps the team guessing about who may have sent him a particularly thoughtful Christmas present. Meanwhile, Cuddy receives an unexpected gift of her own.