Teresa Mendoza returns to Mexico after 8 years to fight with Mexican drug dealers.
The adventurers spot a UFO and encounter Professor Icarus, an expert on the subject.
As Callie and Arizona's wedding approaches, the couple quickly realize that the day they've been looking forward to is not turning out the way they'd envisioned. Meanwhile Alex continues to make the other residents jealous as he appears to be the top contender for Chief Resident, Meredith and Derek make a decision that will change their lives forever, and Dr. Perkins presents Teddy with a very tempting proposition.
Raj attempts to cure his social anxiety disorder while Penny uses Bernadette to spy on Leonard and his girlfriend.
Leslie's ex-best friend, Lindsay Carlisle Shay, launches an attack on Pawnee, banning residents from visiting a nearby park in the neighboring city of Eagleton with a large fence, causing Leslie to go to war with Eagleton. Meanwhile, everyone finds out that it is Ron's birthday, a fact that he went to extreme lengths to conceal.
With the arrival of the full moon, Elena tries to prepare for whatever Klaus has planned and Tyler faces his second transformation. The terrifying events quickly spin out of control, despite an unexpected act of courage. Finally, Damon admits the truth to Stefan about a terrible new development they must face...
When a prison guard is stabbed to death outside of a jewelry store, Patrick Jane suspects one of the guard's inmates is the killer. Meanwhile, Rigsby questions his own father about the murder.
Jeff and Audrey get a surprise that their family may soon double in size. Russell in his latest scheme to date a girl decides to throw a party Ford Timmy who recently became a citizen, now the question is will the party have the desired effect for Russell?
When a 15-year-old Jane Doe is found on the streets, it is up to Brennan, Jeffersonian Intern Arastoo Vaziri and the entire Jeffersonian team to figure out her history and if she is responsible for a recent murder
As the Greendale student body enjoys their year-end picnic, Dean Pelton announces plans for a small, quick, safe game of paintball. As the game heats up, alliances are formed - and broken - and friendships are put to the test. When a mysterious and threatening figure emerges on the Greendale campus, it becomes apparent that this is no ordinary game of paintball.
Jill returns from Australia a new woman---or so she says. Her newfound sense of purpose to avoid gossip quickly ends when she dishes about Ramona during lunch with Kelly, LuAnn and Sonja. In addition, Sonja details the group's pecking order dynamic Cindy and Ramona meet for drinks, but tension spills over.
Langston becomes more determined than ever to track down Nate Haskell, the notorious Dick Jane killer, after discovering that he's kidnapped his ex-wife, Gloria.
After Michael learns that Percy has ordered Divison to kill anyone who could decrypt the black boxes, he sends Nikita in to save the last person on the list, a CIA cryptographer named Malcolm. Nikita kidnaps Malcom and takes him to Ryan for protection. Meanwhile, Percy turns on Alex.
The survivors of the explosion at Ravenhill Psychiatric Hospital reunite to bury one of their number killed in the blast, but there is to be no rest for the wicked.
After a rough start to the season, Troy is back in the groove, and on pace to fill his tags. His new sharpshooter Liz has been a large part of his success. But on the swamp, things can change in a heartbeat. During a capture, Liz is injured...and Troy's momentum is suddenly in doubt. Bruce has always hunted solo in the swamp.
Todd and Charlie decide to throw Rajiv an American bachelor party for Rajiv during his wedding, and Manmeet tries to make a good impression as his first meeting with his American girlfriend approaches.