Castle really stepped up his game this episode. He refrained from being the silly Castle because his daughter's life was on the line and even Beckett understood what he was going through. All people in this episode wanted to help Castle by working their hardest including Gates.
In this episode, we get to meet Castle's father who works for the CIA. I'm sure that he'll reappear and play a semi-major role later on. I still can't imagine how smart Castle's father is. He predicted what the kidnapper would try to do and counteracted it. Overall, very good episode and I'm not sugercoating it just because I love Castle. This episode was very good and deserved a 10.