B.K. Cannon

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.

When married couples fostering young children end up being killed in Seattle, the BAU team looks for an unsub with a maternal-yet-murderous instinct. Also, Garcia fears a possible proposition from Kevin. Teri Polo guest stars.

Derek is being sued for malpractice and stays in a depressed state at Meredith's; Alex has an epileptic girl who's most recent seizure caused heart failure; Adele tries to help settle issues between Richard and Bailey.

Frankie is excited to stretch out and relax on her new backyard lanai (aka patio) that Mike and his workmates built for her. But peace and serenity become hard to come by when new neighbors, with three screaming kids, move in next door and make it next to impossible for Frankie to find some quiet time. Meanwhile, Brick questions Mike as to whether his workmates helped build the lanai because they are his friends, or because he's their boss; Sue and Lexie draw a winning number in the dorm lottery and score the perfect room but find it difficult to kick out its current occupants; and Axl and Hutch open up a grilled cheese food truck out of their Winnebago, with a reluctant Kenny as their chef.

The team investigates the death of the leader of the Lynwood University male acapella singing group, “The Whippersnaps,” whose body was found in the school rat lab. The victim recently kicked out Ian Jansen, one of the group’s best singers, sending Booth and Aubrey to question Ian and other current members of the male group and some stars of the competing female acapella group to get a handle on the group dynamics and what could have led to the murder of one of their own. Meanwhile, surprising information about Aubrey’s own college experience is brought to light, Hodgins applies for an experimental nerve regeneration study, Booth tries to plan a summer trip with Parker and a new intern joins the Jeffersonian lab.