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.

Pam accidentally brings lice into the office and lets Meredith take the fall, while Dwight vows to destroy the parasites. Meanwhile, Jim has a fantastic day in Philly wooing a potential business associate. Meanwhile, Phyllis, Nellie and Kevin meddle in Darryl's love life.

Clark brings an espresso maker to the office. Dwight and Clark pretend to be a father-and-son to land a sale. Darryl goes on an interview at Jim's company, where Pam drops by unexpectedly.

Dwight tries to stop Darryl from moving to Jim's start-up company. Jim misses his daughter's first recital, to Pam's dismay. Nellie spills the beans about Pete and Erin.

Pam’s warehouse mural is defaced. Darryl has difficulty dealing with the Jim's cleanliness habits in their apartment. Angela grudgingly allows Oscar and Kevin to attend her son’s first birthday party.

Everyone in the office is excited when promos start running on TV for the documentary. Dwight makes Angela jealous when he starts dating a brussel sprout farmer. Meanwhile Jim has a big meeting with Major League baseball player, Ryan Howard.