Kyle's mum looks so good after her fecal transplant that everyone wants to get their hands on her goods; Cartman and the boys jump into the quest for the best microbiome.
Beavis makes a new friend when he gets injured and starts seeing double. Middle-aged Butt-Head finds out about Beavis's freakishly strong grip and uses it to hustle at a biker bar.
Oscar returns from his long vacation; Andy takes advantage of events to get closer to Michael; Jim gets Karen and Pam to help stage a prank on a new target.
Ryan invites Michael to be a guest speaker at his business school; Dwight battles a bat that is loose in the office; Pam invites co-workers to her first art show.