A local Pawnee group predicts the end of days, causing chaos in the Parks department.
With help from Elena and Bonnie, Alaric tries to decipher the meaning behind his recent discovery Elena and Rebekah engage in a mean-girl power struggle, until Rebekah finally reveals some of her family's ancient secrets and the violent past she shares with Klaus and Elijah. Damon tries a reckless new approach to make a breakthrough with Stefan, and they're both surprised by an unlikely ally.
The doctors become nostalgic when George O'Malley's mother, Louise, returns to Seattle Grace for medical help after a botched surgery at a neighboring hospital; the residents are inspired by a medical miracle when they witness a harvested heart that continues to beat outside the body; a new pediatric fellow excites Arizona and makes Alex feel threatened; Jackson lets his suspicions about Mark and Lexie interfere with his work; and Henry and Teddy have their first marital fight when he expresses interest in pursuing medical school
Amy becomes heartbroken when she discovers that Penny and Bernadette went wedding dress shopping without her.
The gang uses the Internet to cyber-stalk their prey. Frank tries to drum up business for Paddy's with a viral video.
When a drag queen's song makes Hawthorne Wipes an iconic gay product, Pierce embraces it, until his homophobic dad shows up to squelch the idea.
Michael and Fiona plan to abduct a hacker in Puerto Rico in order to obtain his software, but the man has several other enemies to contend with. Elsewhere, Madeline learns to retrieve information from the police under the tutelage of Sam and Jesse.
The search for a serial killer hits close to home for Jane when he encounters a blogger who has devoted his life to finding the killer.
After not hearing from her grandmother for a couple of days, Cassie becomes concerned and wants to go look for her. Diana decides the entire Circle should go in case Jane is in trouble. She also invites Jake along, much to Adam's dismay. A storm turns the day trip into an overnight excursion, so Faye suggests a little game of Truth or Dare to liven up the evening. However, things take a horrible turn when Faye is forced to reckon with someone from her past.
The Machine identifies a school teacher who witnessed a mob hit as their next POI and Reese and Finch rush to save his life.
Dwight installs a Doomsday device that will fire all of the employees and effectively close down the branch if they make too many mistakes. Meanwhile, Gabe attempts to court the new warehouse worker, Val.
Gloria persuades Jay to commit to a night of salsa dancing after seeing how much his friend Shorty and his girlfriend do together. Meanwhile, Cameron makes a bet that he can get a woman's phone number at the bar, and Phil builds a tree house for Luke.
Tate comes face to face with his past, and Ben and Vivien are haunted by a new houseguest before Halloween night comes to an end.
The sun returns after months of darkness, dynamically transforming the landscape. Millions of migrants join the hardy residents as they find mates and begin to breed.
Frustrated with her lack of flying and stuck in a rut as a courier driver, Audrey decides her time at Buffalo is over. Devan, Ian and Jimmy deal with a hydraulic fluid leak in the C-46 on the valley run, which forces Jimmy to crawl into the "hell hole" and crank down the landing gear by hand.
Frankie and Mike are convinced that slacker son Axl will blow his interview with a football scout, which could earn him a scholarship to college. Meanwhile, Sue and Brick begin a texting marathon - and rack up some serious charges - when they discover that Aunt Edie accidentally gave them her cell phone; and Frankie tries to be completely attentive to the family's needs when she realizes that she's more considerate to outsiders than her own kin.
As Coach Daniels prepares to be inducted into the College Hall of Fame, Thad comes to terms with some troubling secrets from Daniels' past while Alex connects with Marty on a new level.
The Graysons’ quiet anniversary plans go off track and are replaced by an explosive family dinner. Meanwhile, Frank unearths some info on Emily in an attempt to prove his devotion to Victoria.