(Part 2) Castle and Beckett remain trapped in the frozen storage container while the NYPD and the Department of Homeland Security continue to search for the dirty bomb. Alexis' worried call finally results in help arriving, including Beckett's boyfriend, Josh. Now back on the task force, Beckett and Castle team up with Homeland Security, to follow the trail of domestic terrorists.
Tropes:
- Crusading Widow: The reason Agent Fallon acts the way he does is because of what happened to his dead wife. She was on one of the planes in 9/11.
- Earn Your Happy Ending: The NYPD and government manage to stop the bomb.
- Good Is Not Nice:
- Agent Fallon is a jackass though he's not being unpleasant for fun, but to stop a dirty bomb attack.
- The Syrian Consulate chief of security is a smug jerk barely bothering to hide his position as a spy and was trying to pressure Hamid into returning to the Syrian weapons programme, but he never did more on the latter task than just talk and he does find a loophole method to pass critically useful information to the team without overstepping his authority.
- Castle, in a downplayed example, tells Martha and Alexis to get out of the city without giving them many details, but he has to tell them they can't tell anyone else. Alexis tries to call her boyfriend and he stops her. All three of them are holding back tears.Martha: Richard, come with us.
Castle: I will as soon as I can.
- False Flag Operation: The true culprits; they're a trio of Right-Wing Militia Fanatic types who believe that the government will happily forget about them and use their attack as an excuse to declare war against Arabs, who they are trying very hard to frame for the attack.
- I Have Your Wife: A variant. The militia group holds Amir's infant daughter hostage to force his widow to drive their bomb into the city.
- Knight Templar: The real bomber is part of a cell of former US soldiers who are convinced the US has given up on the war on terror and want to bomb NYC in the belief that it will spark a renewed desire to murder the Middle East.
- Layout of a Season: Each of its three full seasons has a major two-parter with a big guest star representing a federal agency right about this time. In this season, we have "Setup" & "Countdown", guest starring Adrian Pasdar, playing a member of the Department of Homeland Security.
- The Scapegoat: Amir, and later his wife, were intended to be this for the veterans' plot.
- Shell-Shocked Veteran: The real villains are veterans who have gone off the deep end because the country stopped caring about the war on terror.
- Wire Dilemma: Castle and Beckett face this when they find the bomb and neither have any disposal experience. With seconds to go and nothing to lose Castle just yanks all the wires at once. Thankfully, this works.
