The study group learns about Greendale's first dean, Russell Borchert (guest star Chris Elliott), a brilliant, wealthy recluse who was involved in a scandal and disappeared in the 1970s. Eager to find out more, Annie and Abed (Alison Brie, Danny Pudi) lead a search for Borchert's sealed-off computer lab. Subway, which wants to take over the college, enlists Chang (Ken Jeong) to keep an eye on the study group in the season finale, "Basic Sandwich."
Everyone's thinking about the meaning of fear after Hank's (Kevin Daniels) spider phobia comes out, and Brian (Kevin Bigley) meets a look-alike with a suicidal streak. Johnny (Michael Mosley) is about to be paid back for all the practical jokes he's played in the new episode "Itsy Bitsy Spider." Jessica McNamee and Bill Nunn also star.
Elena and Stefan (Nina Dobrev, Paul Wesley) have disturbing dreams about the life they might have had together. Grams (Jasmine Guy) warns Bonnie (Kat Graham) about changes on the Other Side. After giving Damon (Ian Somerhalder) some unsolicited relationship advice, Enzo (Michael Malarkey) confesses he's looking for a woman he loved long ago. Liv (Penelope Mitchell) spearheads an effort to track the Travelers in the new episode "Resident Evil."
Ben and Leslie (Adam Scott, Amy Poehler) put on a charity auction to raise money for the Unity Concert. Andy (Chris Pratt) gets some help managing his schedule from April (Aubrey Plaza). Donna (Retta) asks Ron (Nick Offerman) for help dealing with an ex-boyfriend (guest star Keegan-Michael Key) in the new episode "One in 8,000." Jim O'Heir also stars.
Mary's (Adelaide Kane) brother James (Joe Doyle) comes to France to talk his sister into returning to Scotland. Suspicious, Francis (Toby Regbo) investigates and uncovers a plot that would destroy Mary, resulting in a rift between them. Catherine and Kenna (Megan Follows, Caitlin Stasey) take drastic measures as the king (Alan Van Sprang) continues to decline in the new episode "No Exit." Torrance Coombs also stars.
Jordan (Laura Bell Bundy) gets drunk and makes out with a prisoner in this new episode. Charlie (Charlie Sheen) is, to put it mildly, not happy about this. Wait, wasn't he the one who wanted her to pose as a prisoner's fiancee a while back? Barry Corbin also stars in "Charlie Catches Jordan in the Act."
In the season finale, Adam and Crosby (Peter Krause, Dax Shepard) re-enact some antics from childhood as they reminisce about those days. Amber (Mae Whitman) struggles to let Ryan (Matt Lauria) go after reuniting with him. Sarah (Lauren Graham) responds to Hank's (Ray Romano) request. Zeek (Craig T. Nelson) surprises Victor (Xolo Mariduena) with a driving lesson. Miles Heizer, Erika Christensen and Sam Jaeger also star in "The Pontiac."
With winter on the way, the miners try to make the best of the time they have left. Josh and Eric arrive in Eqi, north of the Arctic Circle, in search of gold, while Chad and the rest of the team focus on dredging for rubies in the Upper Lake area. First, though, they have to move the dredge, which Chad and Josh dropped in the wrong place, in the new episode "Point of No Return."
Ragnar, Horik and their new ally, Lagertha (Travis Fimmel, Donal Logue, Katheryn Winnick), set sail for Wessex, but the two men disagree on the real reason for the trip. Princess Aslaug's (Alyssa Sutherland) latest prophecy comes true as she prepares to give birth again in the new episode "Boneless."