We first meet mystery man Richard Castle at a crowded Manhattan party where he’s halfheartedly doing the press tour thing. The bash celebrates Castle’s latest and last novel in his successful Storm book series. His publisher/ex-wife, Gina, has grown accustomed to Castle’s healthy alimony checks. So she’s more than a little ticked that he’s killing off their billion-dollar business because of a little writer’s block. At a murder scene, Detective Kate Beckett (Stana Katic) studies the flowery corpse of 24-year-old Alison Tisdale. Beckett can’t shake an uncanny feeling of déjà-vu. But why?
Back at the party, Castle asks his flamboyant mother, Martha, if she started the writer’s block rumor. Martha dismisses the charge by chasing after a silver-haired gentleman. Castle confides to his sassy teenage daughter, Alexis, that he ditched his mega-popular book series because everything was becoming too predictable. Perhaps he just needs a little inspiration. Enter Beckett—flashing her badge. These two need to talk.
Down at the precinct, Castle tries to flirt with Beckett. He fails miserably. Beckett shows Castle photos of the murder victim. He quickly realizes it matches a scene from one of his books, Flowers For Your Grave. The case of another recent murder victim, small-claims lawyer Marvin Fisk, mirrors a scene from Castle’s Hell Hath No Fury. After Castle leaves, perplexed, we discover the buttoned-up Beckett is a closet Castle fan. Ha! Much to Beckett’s chagrin, Castle is allowed to assist her on the case. Flirtatious banter ensues. Castle does some pointed armchair psychology on Beckett. But does he peg her correctly? We don’t know her well enough to be sure. But we can’t wait to find out.
The two new partners discover the next victim: a woman face down in a rooftop pool, wearing a yellow evening gown and a tiara. Castle recognizes it as the murder from his Death of a Prom Queen. More copycat action! They get a match on some prints—Kyle Cabot of Brooklyn. The cops enter Cabot’s place where they find a boatload of creepy evidence and Cabot, himself, chanting, "Get out of my house!" At the precinct, Beckett, Castle and Beckett’s boss, Captain Montgomery, watch as Kyle rocks back and forth in the interrogation room. The suspect looks to be a fairly disturbed fellow, so the cops think he did it. Castle doesn’t. We’re gonna go with our instincts and side with the civilian. As Beckett delves deeper into the investigation, she begins to have doubts as well. Castle steals Beckett’s file (by way of flirting/distracting) and eventually clears the obsessive Cabot. The guy was set up.
The dynamic/flirtatious/combative duo zero-in on an heir to a fortune to be gained following Tisdale’s death—her brother, Harrison. But, alas, his alibis all check out. Nevertheless, Castle and Beckett get a search warrant while Harrison races home to shred some evidence. When they arrive at Harrison’s place, Beckett handcuffs Castle to the car. She doesn’t want him getting in the way. Fortunately, Castle manages to get unshackled just in time to chase an escaping Harrison. Beckett catches up to them, as Harrison holds a gun on Castle. We discover that all those days of spinning murder mysteries have really paid off, as Castle figures out the true motive behind Alison Tisdale’s murder. Castle explains that Alison wasn’t just killed her for cash. Harrison also wanted to punish his father for preferring Alison over him. A quick elbow move allows Castle to knock the gun away from Harrison and Beckett takes it from there.
Back home, Castle taps away at his computer. Finally inspired, he's writing again. The next morning, Castle returns to the precinct. He’s basing the main character of his next set of novels on Beckett—and he’s asking to do more research. Looks like this could be the beginning of a…of a… Well, we have no idea what this will be. But we can’t wait to find out. Because everyone loves a mystery.