(Part 2) After barely surviving an explosion that destroys her apartment, set by the serial killer, now identified as Scott Dunn, Beckett pushes Shaw's imposed boundaries on her involvement in the investigation, and gets herself removed from the case. But when Dunn kidnaps Shaw to get to Beckett, Beckett takes over the investigation and finds herself relying on Castle's instincts as a mystery writer to save Shaw and herself.
Tropes:
- Awesomeness by Analysis: Castle gets in the killer's head and realizes that he's leading the CIA into a trap, even figuring out where the asshole is watching from.
- Badass in Distress: Agent Shaw gets kidnapped by Dunn.
- Booby Trap: Castle figures out that Dunn lured the other agents to be killed by the bomb. While Beckett goes after Dunn, Castle frees Shaw, telling her that her men are sitting on top of about 19 pounds of cyclonite.
- Book Ends: In the previous episode, Castle stayed the night and made Beckett pancakes in the morning because her bacon and eggs were bad. This episode, Beckett stays the night and makes bacon and eggs in the morning.
- Defiant Captive: Even as a hostage, Shaw has no time for Dunn's ranting. She even managed to break his nose.
- 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 "Tick, Tick, Tick..." & "Boom", guest-starring Dana Delaney, playing a specialist from the FBI.
- Naked Freak-Out: A relieved Castle finds Beckett alive after surviving a bomb attack. Although to his shock or delight, she was naked at the time.
- Writing About Your Crime: The team finds the killer's hideout, and with it several manuscripts of his previous crimes, including his current one regarding Nikki Heat (Beckett).
