Another hugely entertaining episode from Castle, which in my opinion is proving its worth with each new installment. I really do hope the network realizes that and doesn't cancel it.
The case is about a little girl who has been suddenly abducted from her home. Her father is a painter and he proves to be a negligent parent, since he is working while listening to his i-pod, leaving his daughter in another room to watch TV. He only notices she went missing after a while. Since the case isn't technically a homicide it is outside Beckett's jurisdiction, but she gets called in for the case by the FBI agent in charge, who (not so coincidentally) happens to be her ex-boyfriend. So as expected there is competition between him and Castle. Castle is clearly interested in Kate and I think that if in the previous episodes he was only flirting with her and we kind of got the impression he hadn't really made up his mind, his behaviour in this episode confirms he is seriously interested. Ellers (the FBI agent) also tries to win Kate back, but it seems like a done deal for her. The whole interaction between the two men is very entertaining, as they're both smart interesting people, and they come up with great lines to throw at eachother. But I was glad Kate didn't get back with Ellers, she and Castle are great together.
The case is solved when Castle notices what initially seems like an insignificant detail, and it is revealed that the painter's wife had arranged the "kidnapping" with her sister, in order to pay the ransom money to herself and then sue her husband for negligence and get a divorce in her favour. It seems cruel and ruthless at first but then she has her say and you get to see her side of the story. She was extremely tired for having to work long hours to support the family, and didn't want to pay alimony to her husband and lose custody of her child, as she didn't think the husband was fit to take care of her. "How can you hate me so much?" he says to her and she replies "You made it easy". So in the end it's just two very different people finding themselves on completely opposite sides, and it's hard to judge any of them. The husband did what he thought was his calling, but in the process his wife felt she was taken advantage of.