It's Halloween in the office and Andy invites his college a cappella group to perform, which leads to a confrontation with his frenemy Broccoli Rob. Meanwhile, Dwight finds evidence that a madman is loose in the office and tries to track him down, and the first meeting of Jim's new job causes a fight with Pam.
Elenco: Rainn Wilson , John Krasinski , Jenna Fischer , Brian Baumgartner , Oscar Nunez , Angela Kinsey , Craig Robinson , Ed Helms , Leslie David Baker , Phyllis Smith , Ellie Kemper , Creed Bratton , Kate Flannery , Jochen Busse , Thorsten Nindel , Ulrike Bliefert , Jake Lacy , Clark Duke , Ali Hartman , Susanne Hartman , Catherine Tate .