The episode was even titled "Murder He Wrote". He mentions that it feels like he is Jessica Fletcher in an episode of Murder, She Wrote. An episode invokes this when Castle goes to devote a enjoyable weekend in the Hamptons (far more specially, with Beckett, who is now his girlfriend) but a murder sufferer stumbles into his yard and dies in his pool, wrecking the Two-Person Pool Party that was about to go down.