When a half-naked woman is found covered in caramel sauce and hanging by bondage cuffs in a public park, Castle and Beckett's investigation takes them into New York's underground world of sexual domination. Naturally the case serves as sexy fodder for the

Castle and Beckett investigate the murder of a dead man found in a family's house that just returned from vacations. Meanwhile, Castle is elected as one of New York's 10 most eligible bachelors.

Castle and Beckett investigate the death of an Irish mobster, but while on the case they uncover what may be an international drug smuggling operation, as well as the killer may be involved in the murder of Beckett's mother.

Castle and Beckett are called to a wedding to investigate the murder of a bridesmaid. Castle realizes that the wedding is from a former girlfriend Kyra. Everyone's feelings are compromised, since Kyra has doubts about who she is marrying, Castle's feelings may not be as objective in the case and Beckett picks up the connection between them, making her a little jealous and have poor judgement.

Castle and Beckett investigate an art dealer that is shot in his gallery, but the bullet is inexplicably missing from the crime scene. To add to that, the only witness suffers from amnesia.

Castle and Beckett investigate the murder of a man stuffed down a garbage shoot. Things get complicated when both his wife and fiance come in to identify the body.

Castle and Beckett investigate the murder of an Assistant District Attorney.

Castle and Beckett investigate the murder of a bike messenger and the past of a prominent family figures into the investigation.

Castle and Beckett investigate the murder of rock star on the rise, in which the body is found like a scene from her latest music video.

It's close to Halloween, and a man is found murdered in a graveyard - with a stick through his heart, and sporting fangs. Castle and Beckett track the murderer to a vampire cult, all the while Castle is trying on costumes for his Halloween party - costume mandatory!

Castle has a new book agent, Paula Haas, but she talks with him when he has gotten an opportunity that may change his career. The downside is that taking the opportunity would mean the end of his relationship with Beckett. Meanwhile, an unidentified woman is found dead in a manhole.

Castle and Beckett investigate the mysterious death of an Arctic explorer during an expedition. The investigation leads them in many interesting directions including Park Avenue and the CIA. Things really gets frustrating when Castle wonders if the killer is fooling all of them.

It's fashion week and Castle and Beckett get to see what happens in the background as they investigate the murder of a model.

Castle and Beckett compete against Ryan and Esposito to see who can solve their murder case first. A few twists make the two teams work together to figure things out.

Castle has a lot going on. He's trying to finish his new novel Heat Wave and trying to figure out how to fix things with Beckett. They find themselves working together to solve the murder of a man found tangled in tree limbs.