S6, E26: Whistleblower
The press finds out that Sabre's printers catch on fire. Jo (guest star Kathy Bates) shows up to the office in hopes of finding out who the whistleblower is. Everyone suspects Andy (Ed Helms), who adamantly denies he leaked the information. Steve Carell, Rainn Wilson, 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.