"Knight Fall" is the eighteenth episode of the sixth season of the American medical drama House and it is the 128th episode overall. It aired on April 19, 2010 and was directed by Juan J. Campanella.A knight in shining armor, William, becomes House's next patient. Foreman and Thirteen go to the Renaissance Fair to investigate.Meanwhile, Wilson's new girlfriend is his first ex-wife. House confronts him and tries to ruin their relationship to protect him from being hurt again.