With enough credits to graduate, Jeff contemplates his future. The study group once again is faced with the darkest timeline.

Sherlock agrees to take a case from a man claiming to be Moriarty, hoping it will bring him closer to finding his nemesis. Meanwhile, Gregson encourages Joan to give up the dangerous line of work she has chosen and go back to being a sober companion.

It's finally time for Regionals, and the glee club is more determined than ever to advance to Nationals. Brittany returns from her MIT trip with a new attitude and Ryder finally has a lead on who is "catfishing" him.

The doctors of Grey Sloan Memorial Hospital prepare for a super storm heading towards Seattle. Owen's desire to be a parent gets stronger as he becomes closer to Ethan. One wrong move puts the lives of Meredith and her baby in jeopardy. Meanwhile, Jo looks to Alex for help in a moment of crisis, and one doctor gets the shock of her life.

When the BAU investigates a murder involving organ removal Jack believes that the Chesapeake Ripper may have resurfaced, but Will determines that the victim's murder is the result of illegal organ harvesting accident. Meanwhile, Will suffers from nightmares where he is Abigail's father, and Hannibal slowly starts to seduce Alana Bloom and begins to visit his own therapist, Dr. Bedelia Du Maurier.

Animal expert Jack Hanna; from "Star Trek: Into Darkness", actor Benedict Cumberbatch.

Finch and Reese team up with unexpected allies as they race to fix the machine; as Detective Carter tries to apprehend Cal Beecher's murderer, she finds herself up against HR -- a criminal organization.

The White House is in the middle of its biggest scandal to date and Cyrus is in the eye of the storm. Meanwhile, someone close to Olivia betrays her and the team.

Amy and Sheldon's relationship takes a surprising turn during a game of "Dungeons & Dragons"; Lucy and Koothrappali have an awkward date.

Carey Mulligan divulges a dark secret, Jennifer Egan discusses "The Great Gatsby"'s place in American letters, and Baz Luhrmann pays homage to F. Scott Fitzgerald.

Comic/actor Bob Saget; from "Modern Family", actress Sarah Hyland.

Jim convinces Dwight that he needs to choose someone to act as an Assistant to the Assistant Regional Manager; the two subsequently hold tryouts for the position. After her daycare turns away her child, Angela is forced to bring her kid to work. Andy auditions for "The Next Great A Cappella Sensation".

As Graduation Day approaches, Caroline tries to distract Elena by focusing on simple tasks like sending out announcements, but Elena won't be swayed from her new obsession. Sheriff Forbes calls Damon and Stefan to the hospital, where someone has been attacking patients. Still trying to force Katherine to help her, Bonnie refuses to give up on her plan to defeat Silas. As a violent wind storm causes a power outage in Mystic Falls, ghosts suddenly appear - some with good intentions and some bent on revenge.