Sherlock is called in to investigate when a supposedly uncrackable bank vault called “The Leviathan” is breached. Meanwhile, Joan is pleasantly surprised when Sherlock meets her family and defends her choice to become a sober companion.

A tribute to the film "Love, Actually" with five different storylines all dealing with the holidays. Sam and Brittany live as if it's the end of the world as the Mayans know it. The Puckermans, including half-brothers Puck and Jake and their mothers, come together for Chanukah. Artie suffers a head injury in which he slips on ice and has an epiphany through a dream sequence. He wonders what may have happened if he was never in a wheelchair and glee club never formed. His black-and-white vision has Rory as his guardian angel, reminding him of who he was to the glee club. Kurt spends Christmas with Blaine and his father in New York, whilst discovering his father has prostate cancer. Sue struggles to get a Secret Santa present for Marley's mother, Millie, but has a change of heart after seeing Marley and Millie struggle.

As the rest of the doctors prepare for Bailey's wedding, Richard helps her through a bout of pre-wedding jitters. Meanwhile, Lizzie butts heads with Meredith, and Callie and Jackson try to convince Derek to participate in a risky surgery that could fix his hand.

Every member of The Gang has something to celebrate at Guigino's, Philly's finest eatery, but when Mac and Dennis' private dinner is interrupted by an unexpected sighting of Frank and Charlie, the in-fighting begins. Dee also turns up at a table for one, and over the course of the night, the "one-ups-manship" soars to new heights.

From "Django Unchained," actor Jamie Foxx; from "The Talk," co-host Julie Chen; musical guests DIIV

As the FBI pursues "the man in the suit," Reese is even more determined to protect the latest person of interest after learning she is the sister of a soldier who was killed in action.

While working in the White House, Olivia helps Vice President Sally Langston; Cyrus stumbles across the truth about James's secret investigation; and one of Olivia's associates struggles to come to terms with a shocking betrayal.

During a game, Sheldon revisits Christmas memories; Amy, Penny and Bernadette look for a date for Koothrappali.

Rockers raise money for Hurricane Sandy victims, Vince Gilligan leaks "Breaking Bad" footage, Colbert Super PAC money finds a home, and Simone Campbell talks social justice.

From "Take It All", host Howie Mandel; from "Hyde Park on Hudson", actress Olivia Williams.

Kevin is blackmailed by Ellie's boyfriend, Taco helps Ruxin with his fertility issues, and Pete re-connects with his high school crush Gina Gibiatti.

Andre starts dating his interior decorator and discovers that the buyer of his old loft is Deion Sanders. Rafi and Dirty Randy prepare for the end of the world.

As a Winter Wonderland-themed party fills the streets of Mystic Falls, Stefan and Caroline find themselves at odds with Tyler over his plans for Klaus and his hybrids. When Caroline proposes a solution to their problem, Hayley finds a dramatic way to make it clear that she is not on board. Later, Klaus makes a discovery that leads to chaos and violence. Meanwhile, Elena and Damon retreat to the Gilbert Lake House to help Jeremy conquer some dangerous inner demons with the help of Bonnie and Professor Shane, who reveals a piece of ancient history that leaves them all speechless.