Finding it difficult to mend fences with Tommy and Diggle, Oliver instead focuses on crossing another name off the list. While digging through a crooked accountant’s laptop, Felicity discovers a transaction that could help Oliver find Walter. To reconfirm the lead, Oliver gambles that Felicity can be counted on in the field for the first time. In a flashback, Malcolm reveals to Robert Queen and Frank Chen painful details surrounding his wife’s murder, and how that shaped his plans for the Glades. Meanwhile, Tommy stuns Laurel with the truth.

Accused of sexual misconduct by a former paramedic candidate, Severide faces potentially dire consequences and fights for his survival both within the Chicago Fire Department and the legal system. Detective Voight returns, looking to collect on the favor that Dawson owes him for helping her brother, Antonio. Casey falls back into old patterns in his personal life, while Dawson, Herrmann and Otis become the proud owners of a real neighborhood bar as Molly's prepares for its grand opening.

The BAU travel to Rapid City after two male victims are discovered murdered in a ritualistic manner. Also, Reid continues to grieve over Maeve’s death.

The CSI team investigates a popular spiritual retreat when a body is found floating in a mud bath. Meanwhile, Hodges questions his marriage plans to Elisabetta.

From "The Great Gatsby", actor Tobey Maguire; Stupid Pet Tricks; musical guest Tom Odell.

When a concert turns into a mob scene, a teenager is brutally assaulted; Detective Amaro ends up defending the prime suspect's reputation.

Phil is jazzed to share the wonders of residential real estate with Luke and Manny’s classmates for career day. Gloria challenges Jay’s claims of always wanting to become a novelist. Mitch and Cam make a costly mistake while executing tooth fairy duties.

The 10th anniversary starts off with the busting of JATO rocket car.

Liam invites Rayna to run away with him to finish her album, and Deacon is surprised by his own reaction, as well as Stacy’s accusations; Jolene warns Juliette about Dante’s loyalty, which only drives the two women further apart; Teddy faces off with Peggy about the leaks, and in the wake of her father’s illness, Tandy proposes a new alliance to Coleman. Meanwhile Gunnar tries out some new music, and Avery and Scarlett reconnect.

When Sam and Dean receive a distressing video message from Kevin Tran, they set about trying to uncover the Third Trial. The boys make a discovery that sends them to a casino in Colorado, to find a mysterious recluse who may be able to fill in the holes in Kevin’s research. Meanwhile, Crowley is on a winning streak. Castiel tries to elude Naomi and the angels hunting him.

When Philip and Elizabeth are ordered to go through with a meeting that could potentially be a set-up, they find themselves confronted with unexpected truths about their relationship. Stan's investigation puts him and the FBI even closer to Philip and Elizabeth.

A Newtown victim's daughter confronts Senator Kelly Ayotte, pro-gun senators lose voters' support, and Macklemore and Ryan Lewis share their album, "The Heist".

Comic Michael Ian Black; actress Lena Headey.

Frankie tries to make Sue appear more popular on Facebook; Frankie's dad (Jerry Van Dyke) makes Mike listen to long-winded life stories; Brick and Axl try to create a viral video.

A best-of look at Season 4 charts the journey of the Top 16 and features unseen footage of the coaches.