Due to Beckett's apartment needing to be fumigated, she decides to stay with Castle for the duration. However, their plans for some alone time together are ruined when Alexis comes down with mono and is forced to stay home instead of going on vacation with her mother Meredith in Paris. Things go From Bad to Worse when Meredith shows up at Castle's doorstep with her luggage, ostensibly to look after Alexis. Beckett becomes rather displeased with the situation to say the least.
Meanwhile, a divorce attorney who only represents women is found murdered in her car. As Beckett and Castle dig deeper, they find that she was looking into something urgent, with someone's life hanging in the balance.
- Call-Back: The episode ends with Castle offering to whip up the smorelette he invented back in season three.
- Distressed Drink Jitters: A divorce lawyer is found murdered, and after the investigation it's revealed that one woman that the lawyer was looking into is in fact the wife of one of their murder suspects...the wife that everyone believed the suspect had in fact murdered. The lawyer had tipped to the fact that she was still alive, and was going to expose her for trying to frame her ex-husband for murder. She's holding a teacup, but begins to falter when Castle and Beckett address her by her original name rather than the pseudonym she's going by now.
- Faking the Dead: Leann Piper faked her own death to get away from her abusive ex-husband and tarnish his reputation in the process by making the world think he murdered her.
- Hypocrite: Beckett accuses Castle of being unable to say no to Meredith when she asks to stay in his apartment, with Castle offering all sorts of excuses. Later on, she finds herself agreeing to go to dinner with Meredith, justifying herself to Castle with a litany of excuses.
- The Missus and the Ex: Beckett is rather uncomfortable with Meredith's presence in Castle's apartment, given what happened the last time she visited. But after Meredith invites her to dinner, they become much more friendly with each other, much to Castle's chagrin. Before she leaves though, Meredith warns Beckett that the real reason her and Castle's marriage fell apart was that she couldn't stand that she knew almost nothing about him while he knew everything about her, causing Beckett to worry about how much she really knows about Castle.
- She Knows Too Much: Leann killed her former lawyer Michelle to keep her from exposing her real identity.
- Straw Feminist: The victim is a high-profile divorce lawyer who only represents women. Ultimately subverted as it turns out the reason she was murdered is because she discovered a woman divorcing her husband had faked her death and framed him for murder.
- Unwitting Instigator of Doom: Michelle's most recent client just happened to be the soon-to-be-ex-wife of Leann's accomplice, Walter. She used the opportunity to dig into Walter's finances in order to solve the mystery of Leann's disappearance (neglecting her current client's case in the process), and was killed after discovering that her former client was very much alive and well, and did not want to be found.
- Villain with Good Publicity: Leann claims that her ex-husband Billy was a "monster" at home, and that he used his fame and influence to convince the media that he was the hapless victim of a Gold Digger.
