begin dating and are still together at the end of the season. They break up early in season six. In the 20th episode of season five, "Simple Explanation", Kutner is found dead in his apartment with a gunshot wound to the head. Because Kutner left no note, House suspects foul play, though the death is accepted by the other characters as a suicide. In the seventh episode of season two, "Hunting", Cameron and Chase have a one-night stand. In the middle of season three, they initiate a sexual relationship that Cameron insists be casual; when Chase declares that he "wants more", Cameron ends the affair. By the end of the season, however, Cameron recognizes that she has romantic feelings for Chase and they begin a serious relationship. After leaving the diagnostic team, they assume different roles at the PPTH, Cameron as a senior attending physician in the emergency room and Chase as a surgeon. They become engaged in the season-five episode "Saviors" (the episode immediately following Kutner's suicide) and are married in the season finale. When Chase rejoins House's team in season six, Cameron leaves her husband and the hospital in "Teamwork", the season's eighth episode. She returns as a guest character in "Lockdown", nine episodes later. Early in season seven, Thirteen takes an unexplained leave of absence. Cuddy orders House to fill her position with another woman, but eventually makes the choice for him: medical student Dr. Martha M. Masters (Amber Tamblyn), who makes her first appearance in the season's sixth episode. Thirteen returns in "The Dig"—the season's 18th episode and the show's 150th—in which the reason for her absence is revealed: she was in prison for six months for having helped euthanize her brother, who was suffering from advanced Huntington's. While Jacobson and Wilde play central characters (as did Penn), they did not receive star billing until season seven. They were credited as "Also Starring", with their names appearing after the opening sequence. In season seven, Jacobson and Wilde received star billing; new regular cast member Tamblyn did not. Recurring characters The first six seasons of House each included one or more recurring featured characters, who appear in multiple-episode story arcs. In season one, Edward Vogler (Chi McBride), the billionaire owner of a pharmaceutical company, appears in five episodes. He donates US$100 million to the PPTH in return for chairing its board. Vogler represented an attempt to introduce