While investigating an explosion that kills two people, Sherlock discovers a crime that’s been lying dormant for years. Meanwhile, Watson encourages Sherlock to finally pick a sponsor.
Cristina and Owen continue to figure out their relationship amidst the pending lawsuit; and Bailey argues with Ben over plans for their upcoming nuptials. Meanwhile, Callie recruits Jackson to help find a solution to Derek's hand, but he is preoccupied by a shocking situation with April.
Caroline does her best to be there for Stefan and Elena in a tough time. Damon tries to convince Stefan to help him uncover Prof. Shane’s motives, but Stefan is intent on carrying out a different plan with Klaus. At the annual Miss Mystic Falls Pageant, Elena and Caroline give April advice on which dress to wear, while Tyler and Hayley work together on a secret project, and Damon confronts Prof. Shane with his suspicions. Alarmed by the vivid nightmares he’s having, Jeremy turns to Matt for help, but the situation escalates sooner than anyone expected.
The designers create edgy, androgynous apparel in a challenge that comes with a twist. Guest judges: Jason Wu and Robert Rodriguez.
Don Wildman examines a trunk that may be evidence of a historic journey through Death Valley, a group of bricks from a Civil War prison break, and a human scalp that tells an astounding tale of frontier bravery.
Leslie and Ben meet with an architect from their rival town, Eagleton, about designs for a new park.
Angela goes to Dwight for help when she learns that her husband is having an affair. Stanley and Phyllis take advantage of Jim when he needs a favor, and Pete distracts Pam as she begins painting her mural.
With Charlie under his wing, Frank cleans up so he can get his hands dirty and help out his old company with one last big merger. An unwritten rule of the bar gets the rest of the gang caught up in a case of mistaken identity.
Mitch and Cam try to save an old tree in the park. Jay takes Manny to a kid's Olympics-themed birthday party. Gloria and Claire have an eventful shopping trip.
One man's bikini-clad woman is another man's mystery, and two friends step up their hat game.
Berk's annual festive sporting competition, the Thawfest games, is underway and all the teens are participating with the dragons for the first time in Viking history. Hiccup is determined to finally best Snotlout, who constantly gloats about being the reigning Thawfest champion, but Hiccup's successes begin to make him arrogant and boastful, much to Astrid's displeasure and disappointment.
In the Season 4 premiere, the ladies learn the identity of the baby who was left on their doorstep. Meanwhile, Melanie gets a job offer from a public-relations firm; and Elka tries to regain the upper hand with Pierre.
An attendee at a popular motivational-speaker's conference in Seattle is murdered and the speaker himself disappears soon afterward. Meanwhile, Garcia is puzzled when Morgan refuses to attend a dinner honoring an old family friend.
Castiel tells Sam and Dean that he’s decided to become a hunter like them. Sam and Dean aren’t sold on the idea but agree to investigate a case Cas found where a man’s heart literally burst through his chest. The guys discover that all the deaths resemble cartoon deaths.
The CSI team lends a hand to local law enforcement on the strip with several arrests until a John Doe is found in car. Also, things become personal for Captain Brass when he discovers some facts about his daughter.
Sister Mary Eunice is terrified to discover a dark angel at Briarcliff; Kit makes a bold move to be reunited with Grace.
Oliver encounters a mysterious woman, Helena Bertinelli, daughter of mob boss Frank Bertinelli, who he can finally be himself with, but he soon comes to realize she's hiding dangerous secrets of her own. Helena is on her own personal mission of vengeance and Oliver is caught in the middle. Meanwhile, Tommy is blindsided by an unfortunate turn of events and turns to Laurel for support.