Oliver discovers that after he and his father went missing, Moira and Thea stopped celebrating Christmas. Determined to make up for lost time and restore a sense of normalcy to the Queen household, Oliver decides to throw the family a Christmas party. Meanwhile, Tommy asks Laurel to spend Christmas with him but she points out that Christmas was also her sister Sara’s birthday and she needs to be with her father. Tommy suggests changing things up might be the best way for everyone to heal but Laurel isn’t sure her father is ready for that.

Oliver discovers that after he and his father went missing, Moira and Thea stopped celebrating Christmas. Determined to make up for lost time and restore a sense of normalcy to the Queen household, Oliver decides to throw the family a Christmas party. Meanwhile, Tommy asks Laurel to spend Christmas with him but she points out that Christmas was also her sister Sara’s birthday and she needs to be with her father. Tommy suggests changing things up might be the best way for everyone to heal but Laurel isn’t sure her father is ready for that.

Frankie worries Mike is tiring of her as their 20th anniversary draws close; Sue tries to get Axl and Brick’s help planning a party for their parents; Axl spoils the end of a book for Brick.

Barney’s developing relationship with Patrice leaves Robin questioning his motives. Marshall’s widowed mother gets back into the dating pool, but he thinks she may be swimming with a shark.

Dangerously close to exhaustion, Carrie continues her hunt for Nazir and begins to suspect there is a mole in the CIA. Roya reveals her true colours under interrogation and Saul finds himself fighting to save his career under unexpected circumstances. Meanwhile, the Brodys struggle to maintain anything close to a state of sanity.

The death of a young botanist leads the team into the lucrative world of medical marijuana, while Cho’s work with the rapid response team brings him back into contact with Summer.

Olivia encounters a very intuitive and oracle-like person named Simone as she looks to recover a key piece of equipment for Walter. Meanwhile, Peter finds himself in a perilous situation as he observes Windmark.

In the aftermath of the deadly Cylon ambush, Coker threatens Becca, forcing Adama to a heated standoff.

Becca discovers a startling new development that will affect the future of the human race. Meanwhile, Coker’s life hangs in the balance as the team holds out hope for a rescue, and Adama has a disheartening realization about the war effort and his place in it.

Sherlock uses his trademark deductive reasoning skills to find the killer of a college professor, Watson gets a call from a former lover who needs her help.