When the dragon riders discover a frozen Skrill, a lightning-powered dragon revered by the Berserkers, they scramble to get it off Berk. But when the Skrill is thawed out and unleashed, Hiccup and Toothless are faced with a battle between both the Skrill and Dagur the Deranged's Berserker armada, which could prove to be more than Hiccup and Toothless can handle.

Jafar brings Edwin to Wonderland in a ploy to trick Alice into using another of her wishes. Meanwhile, Alice tries to enter Jafar's palace, and in the past, Young Jafar's mother dies and sends him to his real father: the Sultan. However, the Sultan is less than happy to see him.

Sheldon's disgust at his accidental discovery and subsequent fame reach a level that compels Leonard and Amy to try to mollify him. Raj needs a temporary place to stay for a week so Howard invites him to stay with he and Bernadette.

Stefan continues to offer Katherine his support while trying to mask his own pain, until Caroline shows up with an unusual form of therapy. After trying to make amends with Caroline, Elena grows so concerned about Damon that she turns to Aaron for help. Later, when Damon tells Elena about a terrible ordeal in his past that he has kept secret for decades, she shares the disturbing information she just learned about her own family. Finally, Aaron decides on a desperate course of action after a conversation with Dr. Wes.

Tune in to see if your favorite singing acts make the cut

When Alvin the Treacherous captures the Skrill, Hiccup, Ruffnut, and Tuffnut go undercover to discover that a truce is in the process of being formed between the Outcasts and the Berserkers to invade Berk with the Skrill as their weapon. The trio must now flee to release the Skrill from their control before the truce can be settled.

When Nathan learns why Debbie is Tom's favorite child instead of him, he decides it's time to fill his parents in on some of Debbie's childhood secrets.

While Simon and Gordon disagree on compromising their values to land a lucrative client, Lauren gets stuck in the multi-million dollar Victoria's Secret Fantasy Bra.

Mary and Francis are forced to rely on one another when the castle is taken hostage, and Catherine shocks everyone when she makes a surprising proposal to try to save their lives. Meanwhile, Bash's mother Diane tells Bash of her plan to have him legitimized.

April's sisters arrive to help celebrate April's upcoming nuptials and quickly get on her nerves. Matthew and Jackson are forced to work together when they witness a terrible accident. Callie and Arizona work hard to reestablish their relationship and Cristina is pressured to live stream an upcoming surgery. Meanwhile, a familiar face returns to the hospital.

Sue Sylvester introduces the episode as a Christmas special that FOX did not allow to air from last year. The members of New Directions audition for roles in McKinley's living Nativity Scene. Meanwhile in New York, Rachel, Kurt and Santana work as Santa's elves at a mall.

While Neal delves further into the mystery of the Codex, Peter takes on a classified espionage case with a fellow FBI agent: his ex-girlfriend.

The all-star clothiers fashion a date-night dress for cartoon wife Marge Simpson to wear for an evening out with husband Homer. The guest judges are actress Abigail Breslin and fashion figures Anthony Ryan Auld and Stacey Bendet.

Walden's date with an accident-prone model goes longer than expected. Meanwhile, Alan dates a woman who shares some surprising personal information with him.

Charlie is pursued by a hot reporter who wants to experience his sex study.

The guys revive some classic jokes at their own expense; they go head-to-head debating nonsense in a humiliating elimination challenge.

Rebecca finally has the informant she's been waiting for in Angie Sarich, the accountant for elusive and powerful drug kingpin Thomas Novak. Angie wants to work with the C.I.U. to take Novak down and start a new life for her and her son, but a shocking connection between Rebecca and Novak puts everyone at risk.

Brody tries to buy the perfect gift for Jenny, but as Mansfield says, "What do you get for the girl who has nothing- Brody's extravagant gift turns the downstairs gang against him and makes Jenny feel uncomfortable instead of flattered. Threepeat over-extends himself to buy matching jet skis and is now desperate for a bonus he's not sure he's going to get.

As the team gets closer to the truth, loyalties are tested and relationships are pushed to the limit. Meanwhile, Cyrus has to deal with his own crisis and he realizes that he may have gone too far.

A bone saw from the Civil War; a large piece of kunzite.

When an investigation goes horribly wrong, Sherlock must testify in an official police inquiry which jeopardizes his and Watson's future with the NYPD.

A customized 1951 Harley-Davidson; a crank organ from the early 1900s.

Jorge Ramos

Jim Parsons, Steve Coogan, Daniel Sloss

Allan Mulally

When BRB is hacked right after the beta launch, Trey and Hobbes get to know each other better as they desperately search the city for their prime suspect. Meanwhile, Mikki takes care of an anxious Mitchell after he runs out of Adderall.

Eric Andre and Hannibal Burress were joined by Chance the Rapper and Mel B.

Anjelica Huston, Jackie Guerrido

Kathy Burke hosts this week, with Miles Jupp and Tim Loughton as the guest panelists.

Jimmy Carr is joined by team captains Sean Lock and Jon Richardson for an episode of best bits from the last series.

This week's theme is Knights and Knaves as Stephen and Alan are joined on the show by Victoria Coren, Sue Perkins and Rev Richard Coles.

Together on Graham's sofa are star of stage and screen, ex-Harry Potter Daniel Radcliffe; comedian Harry Hill; Great British Bake Off queen Mary Berry; actor and writer David Walliams; and music and chat from Sir Cliff Richard.