From abc.com:
\"Wildly famous mystery novelist Richard Castle (Nathan Fillion) is bored with his own success. Then he learns that a real-world copycat killer has started staging murder scenes depicted in his novels. Castle is questioned by NYPD Detective Kate Beckett (Stana Katic), a bright and aggressive detective who keeps her investigations under tight rein. Though they instantly clash, sparks of another sort also begin to fly, leading both to danger and a hint of romance as Castle steps in to help find the killer. And once that case is solved, he and Beckett build on their new relationship as they look to solve more strange homicides in New York - as much fun as one can have with death and murder.

Castle is kept grounded by his Broadway diva mother, Martha Rodgers (Susan Sullivan), and quick-witted teenage daughter Alexis (Molly Quinn). Also starring in the series are Ruben Santiago-Hudson as NYPD Captain Roy Montgomery, Tamala Jones as Medical Examiner Lanie Parish, Jon Huertas as NYPD Detective Javier Esposito and Seamus Dever as NYPD Detective Kevin Ryan.\"

Richard Castle, a popular crime novelist, is called to assist the NYPD to help catch a killer who is re-enacting murder scenes from his books.

A young woman is found dead in a dryer in an upscale apartment\'s laundry room and Castle tags along with Beckett to investigate.

A young man is found dead on a boat and the team investigates, but the boy\'s friends do everything they can to thwart the investigation.

Beckett and Castle investigate the death of a New York City councilman who is running for re-election while Castle\'s final novel hits the bookstores.

A woman\'s frozen body is uncovered at a construction site and the investigation forces Beckett to face some issues from her tragic past.

Castle joins the team to investigate a series of murders connected to a Vodou ritual, but he is distracted by his ex-wife\'s presence in town.

Castle and the detectives investigate a woman who was robbed and stuffed in her safe and try to find the connection to the recent string of high-end home invasions.

The team investigates the death of a woman who was found drowned in a motel bathtub full of motor oil and discover that she is a wanted criminal.

Beckett is called in to help the FBI find a missing girl and ends up being partnered with her ex-boyfriend, which causes Castle to compete for Beckett\'s attention.

Beckett and Castle investigate the murder of a plastic surgeon. Meanwhile, Alexis prepares for her first prom and Castle discovers information about Beckett.

Castle ends up being a witness to a crime and Beckett reluctantly agrees to let him tag along for one last investigation.