09/16/2010 (08:00PM - 08:30PM) (Thursday) : MICHAEL SUSPECTS HIS GIRLFRIEND IS CHEATING�AMY PIETZ ("ALIENS IN AMERICA,""CAROLINE IN THE CITY) GUEST STARS�Michael (Golden Globe winner Steve Carell) suspects Donna (guest star Amy Pietz) is cheating on him and puts P.I. Dwight Schrute (Rainn Wilson) on the case. Meanwhile, Andy (Ed Helms) is frustrated when no one takes his customer's complaint seriously. John Krasinski, Jenna Fischer, Leslie David Baker, Brian Baumgartner, Kate Flannery, Mindy Kaling, Angela Kinsey, Phyllis Smith, Oscar Nunez, Creed Bratton, B.J. Novak, Ellie Kemper, Paul Lieberstein and Craig Robinson also star.