When House discovers that the experimental drug he's been using causes fatal tumors, he decides to attempt to excise them himself. However, he can't complete the surgery and needs Cuddy's help. Meanwhile, Thirteen's friend from prison and relapsed drug user, Darrien, arrives at her apartment unannounced, needing medical care after being stabbed. With her friend unwilling to go to the hospital, Thirteen enlists Chase's assistance when the friend loses sensation and movement in her arm. Also, Taub receives some unexpected news that could change his life.