Castle and Beckett's romantic getaway in the Hamptons is ruined when a dying man falls into Castle's pool.
- Busman's Holiday: All Castle and Beckett wanted was a nice trip away where they could relax and have themselves some sexy times. But of course, a dead body has to come right to their doorstep... or rather, it comes to their swimming pool, but that's just semantics.
- Dirty Cop: The killer was one of the sheriff's deputies who stumbled upon a drug ring.
- I Know You Know I Know: While he doesn't say it out loud during his call with Castle, Ryan all but states that he knows Beckett is there with him and they silently freak out accordingly.
- Internal Reveal: Ryan finds out that Beckett's new boyfriend is Castle.
- Mistaken for Prostitute: The Hamptons cops assume Beckett is a prostitute hired by Castle until the sheriff looks her up and finds out that she's a detective.
- Pulling the Thread: Castle spots that the case against the methhead is weak and can't stop obsessing about the case, so Beckett lets him make some coffee and start a proper investigation.
- Secret Relationship: Beckett and Castle are still trying to keep their relationship a secret, while Ryan and Esposito are determined to find out who Beckett is seeing.
- Secret Secret-Keeper: Ryan finds out about Beckett and Castle but decides to keep it to himself.
- Serious Business: Halfway through Ryan's interrogation of Lerner, Ryan hears about Castle's secret girlfriend and the interrogation turns entirely to figuring out who she is. Lerner and his lawyer are both confused but go with it.
- Shout-Out:
- The episode's title is a reference to Murder, She Wrote (stated to be an inspiration for the show from the beginning).
- A New England beach with a Chief Brady? That's Jaws (Okay, he was Chief Brody).
- Brady lampshades his Scooby Doo reference, pointing out that his lieutenant would have gotten away with it if not for Castle and Beckett.
- Skewed Priorities: While interrogating a suspect who was previously interrogated by Beckett in the Hamptons, Ryan is far more interested in the identity of Beckett's boyfriend than he is in the murder.
