After Beckett and Castle find a married woman named Allison Goldman drowned in a bathtub filled with motor oil, their investigation uncovers the victim's surprising connections to the bombing of an oil tanker in 1989.
Tropes that appear in this episode:
- Asshole Victim: Cynthia Dern, unrepentant terrorist and murderer.
- The Atoner: Allison turned out to be a former Eco-Terrorist named Cynthia Dern who was trying to make amends for her involvement in the bombing by surrendering to the FBI and working with Lee Wax to write a memoir explaining what happened. Later on, it surfaces that Susan Mailer secretly sent money to the Pike family on a monthly basis for 20 years, having known about the medical bills they are faced with. As for Cynthia, she felt zero remorse whatsoever.
- Based on a Great Big Lie: Everything about Cynthia's memoir is self-serving, as her true motives for working with Lee were to both keep herself out of prison and earn herself as much money she could from the sales of said memoir.
- Big Bad: Susan Mailer is played up as the episode's posthumous main antagonist because of how her actions in 1989 continue to hang over the episode's plot in spite of her death. Ultimately, when all is said and done, it's Cynthia Dern who truly fits the bill.
- Biography: Something similar to it is a central plot point. To elaborate, Cynthia Dern was having Lee Wax, a ghostwriter, write her memoir on her behalf. Too bad the latter slowly caught on to the former's endless string of lies and informed her publisher about it.
- Deceased Fall-Guy Gambit: Cynthia was attempting to pull this off with Susan, but it backfires and culminates in her own death instead.
- Driven to Suicide: This is how Cynthia wanted for Susan's death to be perceived by the public.
- Eco-Terrorist: Cynthia, Jared, and Susan were all this back in 1989.
- Evasive Fight-Thread Episode: The episode's poker sub-plot. In the first game, Castle has a winning hand, but he folds and deliberately lets Beckett win, because he doesn't want to embarrass her in front of Montgomery, Ryan, and Esposito. A few scenes later, Beckett figures out what happened, returns the money, and insists on a rematch where Castle won't hold back. At the rematch, the same events play out in reverse: Beckett gets a winning hand, but folds and lets Castle win, because she doesn't want to embarrass him in front of his friends. Then it's Castle's turn to take offense at Beckett's charity and demand a no-holds-barred rematch. The episode ends with Beckett and Castle starting one last game, completely alone in her office, with gummi bears and pride as the only stakes.
- False Friend: Cynthia to both Jared and Susan.
- Faux Affably Evil: Susan recalls to Beckett and Castle how Cynthia said the quote below to her moments before her plan to drug and murder her backfired.Cynthia: Let's toast to old friends.
- Femme Fatale: Lee Wax is not above acting seductive to Castle in the hopes of getting information she could use for her next true crime story.
- Freudian Excuse: Cynthia wanted Susan dead for her Deceased Fall-Guy Gambit, and once the latter figured that out, a struggle ensued that ended in Cynthia losing her balance and hitting her head on the sink. Wanting it all to be over, Susan dragged her to the oil-filled tub and pushed her in.
- "Get Out of Jail Free" Card: Cynthia's memoir was meant to be this for her, as she wanted potential jurors to sympathize with her and not want her to be punished because of how "remorseful" she was.
- Given Name Reveal: Less than halfway through the episode, it's firmly established that Allison's real name was Cynthia Dern.
- Greed: Aside from keeping herself out of prison, Cynthia also wanted to make sure she earned as much money as she could from the sales of her memoir.
- Healthcare Motivation: Needing to pay lots of medical bills so that her husband Sam Pike can continue to be cared for, Eleanor accepts the money that's been sent to her on a monthly basis, telling Beckett and Castle that she "did what [she] had to do to survive."
- Heel–Face Turn: Jared underwent this shortly after the botched bombing due to the remorse he felt for his role in Susan's demise. Susan herself—who also survived—felt contrition for how Captain Sam Pike was injured in the explosion, prompting her to send money every month to him and his family.
- Never Found the Body: According to Cynthia, Susan was vaporized when the bomb exploded. In reality, parts of her right arm, her neck, and her face were scarred as a result. Susan was also thrown overboard, after which she was nursed back to health by a friend of hers.
- Never Suicide: Cynthia intended to murder Susan and then let the public believe that she "committed suicide out of guilt."
- No Honor Among Thieves: Cynthia lived and breathed this trope, betraying Jared in 1989 and then conspiring to do the same to Susan in 2009.
- Red Herring:
- Adam Pike, the son of Sam Pike (the ship captain injured in the bombing) and his wife Eleanor, becomes a suspect after it's uncovered that he had been following Cynthia around for weeks. He just wanted to tell her that her "blood money wouldn't buy [his family's] forgiveness," and spent an hour pacing in the hallway while trying to muster the courage to knock on her motel door. Adam chickened out, but not before noticing a woman entering Cynthia's room and talking to her. The woman in question just so happens to also be the real sender of the "blood money."
- Lee Wax is also suspected of being Cynthia's killer, especially after Adam clarifies that Cynthia's killer was a woman. In actuality, she was eating dinner with her publisher until after 12:00 AM on the night that Cynthia died.
- Samus Is a Girl: Early on in the episode, Lee Wax is revealed to be a woman.
- Self-Disposing Villain: Susan was this since she was killed by the very same bomb that she insisted on not defusing. It's BS. Susan wanted to defuse the bomb, but Cynthia wanted for them to return to Jared's car. The latter then ran off by herself when the former followed through with her attempt to shut the device down.
- The Sociopath: Anonymously calling the FBI and letting them know of Jared being at a motel after he refused to escape to Canada with her, Cynthia Dern stole the identity of Allison Porter, a three-month-old baby who died in 1963. Meeting and marrying Michael Goldman, she didn't hesitate to use financial setbacks as an opportunity to not only try to frame Susan for the bombing through a memoir, but also keep herself out of prison. When she found out about Susan still being alive, she conspired to lure her to a motel room, give her a drugged glass of wine, and drown her in a tub filled with motor oil. All in all, she was an incredibly manipulative and self-centered woman who lacked any empathy for others.
- Spotting the Thread: Jared recounts to Beckett and Castle how he was told by Cynthia that the Time Bomb he constructed exploded earlier than they anticipated, killing Susan in the process. However, Cynthia told Lee Wax that she argued with Susan about the bomb once they knew Captain Sam Pike was aboard, backing out when Susan refused to halt their plan. This eventually leads to the discovery that it was Cynthia who wanted the bomb to detonate, and that Susan unsuccessfully tried to defuse the device, with the ensuing explosion throwing her overboard.
- Time Bomb: In 1989, Jared constructed one of these for the bombing of the oil tanker, and it had a three-minute timer.
- Tragic Villain: Nursed back to health after the bombing by a friend of hers and deciding to live under the alias Mary Wright, Susan Mailer sent money to the Pikes every month for 20 years and didn't contact anyone from her former life, including her parents. Then Cynthia suddenly resurfaces in 2009 during her plot to make Susan the scapegoat, setting off the chain of events that resulted in Susan killing her.
- Two Aliases, One Character: Allison Goldman (née Porter) was Cynthia Dern, and Mary Wright is Susan Mailer.
- Very Loosely Based on a True Story: The Exxon Valdez oil spill on March 24, 1989, serves as a motive for Cynthia, Jared, and Susan setting off a bomb on another oil tanker later that year.
- Was It All a Lie?: After finding out who his wife truly was, Michael quickly figures out that "[their] whole life together was a lie."
