As Abby and Jaha each try to establish their authority, Clarke comes up with a plan to stop the Grounders' attack. At Mount Weather, Jasper, Monty, Miller and Harper plan…

Haley is turning twenty-one and the whole family is taking her to a bar to celebrate! Claire really wants Haley to start seeing her as a friend rather than her…

Nyssa returns to Starling City and tells Oliver that her father, Ra’s al Ghul has given Oliver 48 hours to find Sara’s killer or the League of Assassins will start…

Frankie loses her Christmas spirit, Mike unsuccessfully tries to exchange the new family Christmas tree, and a fight over Rudolph the Red Nosed Reindeer threatens to break up BossCo.

Coulson and Whitehall's forces meet in an explosive confrontation that dramatically alters everyone's fates. Meanwhile, Skye discovers shocking secrets about her past.

Barry finds himself face-to-face with his nemesis, the man in the yellow suit, a.k.a. Reverse-Flash, who killed his mother. Barry is frustrated when the Reverse-Flash escapes, but Dr. Wells and…

When Eliza confesses her feelings to Henry, he avoids the subject by focusing on the company's annual karaoke party.

When an ER physician is gunned down in the street, Castle and Beckett soon discover that the victim was a mob doctor to a Mafia family run by an old…

The security breach at the Embassy has far reaching consequences.