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 friend of Castle’s. Also, against this backdrop of Christmas, Esposito and Lanie reach a defining moment in their relationship.
The security breach at the Embassy has far reaching consequences.
Lisbon goes undercover as a prison inmate in order to get a convict to turn on her boyfriend, who is the leader of a high-end car theft ring.
Neal hasn’t heard from the Panthers in days and he’s worried that either Keller turned on him or Woodford simply decided to cut him out of the deal. Using the algorithm Neal stole for the Panthers, the team is able to determine that the Panthers are targeting something arriving at the San Francisco airport. But without enough time to make it to the West Coast, Peter is forced to pass on the task to the local FBI office. Meanwhile, Mozzie comes face to face with his wife, who he met on a con, married on a whim, and hasn’t seen in five years. She insists that she’s reformed and wants to start a new life (with someone new), but Mozzie isn’t convinced, and asks Neal and Peter for help.
Tensions run high between Clarke and Finn, while Raven discovers that Mount Weather is interfering with their communication systems. Meanwhile, Jasper and Monty discover the truth about what’s going on at Mount Weather and Octavia comes face-to-face with her worst nightmare. Finally, President Dante Wallace is about to be betrayed by those closest to him.
When Alex tells Phil and Claire she has a boyfriend, they worry they’ve put too much pressure on her and has made up an imaginary boyfriend. Jay and Gloria both have parties that they are dragging the other to and Jay has a clever plan to get himself out of it, but Manny just might spoil everything. Mitch and Cam just got a beautiful white couch delivered but when Mitch is stuck helping out Brenda, a distressed co-worker, and allows her to stay – it is a mishap waiting to happen.
When Alex tells Phil and Claire she has a boyfriend, they worry they’ve put too much pressure on her and has made up an imaginary boyfriend. Jay and Gloria both have parties that they are dragging the other to and Jay has a clever plan to get himself out of it, but Manny just might spoil everything. Mitch and Cam just got a beautiful white couch delivered but when Mitch is stuck helping out Brenda, a distressed co-worker, and allows her to stay – it is a mishap waiting to happen.
Oliver, Arsenal and Diggle track down the location of a boomerang-wielding killer named Digger Harkness, but are surprised when they come face to face with an A.R.G.U.S. team. Diggle asks Lyla why A.R.G.U.S. is involved but she defers until Harkness attacks the building, killing several agents and targeting Lyla. The Arrow joins the fight and gets help from an old friend — The Flash. Harkness manages to get away and Oliver teams up with Barry again to find him before he can get to Lyla. When Harkness plants five bombs in the city that are timed to explode at the same time, both teams must come together to save the city.
Oliver, Arsenal and Diggle track down the location of a boomerang-wielding killer named Digger Harkness, but are surprised when they come face to face with an A.R.G.U.S. team. Diggle asks Lyla why A.R.G.U.S. is involved but she defers until Harkness attacks the building, killing several agents and targeting Lyla. The Arrow joins the fight and gets help from an old friend — The Flash. Harkness manages to get away and Oliver teams up with Barry again to find him before he can get to Lyla. When Harkness plants five bombs in the city that are timed to explode at the same time, both teams must come together to save the city.
Mike accompanies Sue on a college tour weekend, and Frankie abandons Brick with a school project and a revolving door of babysitters while she goes to see Axl play in his first college football game.