The trial of The Gravedigger hits close to home for members of the team, and everyone at the Jeffersonian must work overtime to uncover the forensic evidence to elicit a conviction.

Greendale Community College is forced to bring in a new Spanish teacher after a shocking discovery about Señor Chang. Troy discovers a trade he truly excels in -- plumbing.

The CSI team must investigate one of their own when Langston is accused by a former colleague of being part of the Dr. Jekyll murders, on part one of a two-part season finale of CSI.

An elderly patient admitted into the E.R. for a heart condition sees a familiar face, a long lost love who happens to be in the E.R. as well for a fractured arm, and the staff find themselves caught up in their love story. Meanwhile, Karev treats a troubled teenage patient (guest star Demi Lovato) whose parents brought her in for schizophrenia, and Meredith can't help but tell Cristina about her suspicions of Owen -- which inevitably messes with Cristina's head.

Actor Alec Baldwin; the National performs.

Leslie is disappointed when her new park plans are put on hold by a visit from two state auditors. April has plans for Andy at her birthday party, and Ann tries to piece together a romantic mystery.

The showdown between good and evil is at hand. With the Apocalypse looming, Sam and Dean realize they are out of options and make heart-breaking decisions that will change their lives forever. A beloved character faces death.

Tonight Stephen welcomes the band The Hold Steady.

Tonight's guests are Robert Downey Jr. and writer Dave Barry. Dave Barry was preempted.

Romantic sparks begin to fly when Patrick Jane and supposed psychic Kristina Frye cross paths again during the CBI investigation into the murder of a charismatic head of a non-profit organization that fights human trafficking.

Michael is surprisingly cheerful after learning some bad news about Donna. The new parents, Pam and Jim, have trouble staying awake in the office. Meanwhile, Angela takes matters into her own hands when Dwight refuses to honor their contract.

Founder's Day has finally arrived, and everyone is busy with last-minute preparations for floats and fireworks. Stefan is uncomfortable with Damon's new attitude toward Elena, but Elena is more concerned about repairing her relationship with Jeremy. Jeremy is worried about Anna, but not sure he's on board with her latest plan for the future. While Caroline is enjoying her day as Queen of the celebration, she also tries to help Matt and Tyler get their friendship back on track. Finally, although Damon and Alaric do their best to stop him, Johnathan Gilbert sets a plan in motion that brings Founder's Day to an end amid chaos, destruction and death.