Unlike many others,I feel this is a good episode. The first one is ok,but I feel this part is better.
I think the writers are trying to get the different view point of American Homeland security. Like 70's FBI and CIA, now day the Homeland Security has the "bad" reputation. This is a episode about them as much is about people's fears(and the action come after that fear, like racial profiling). How easy it's for us as people to generalization an whole race. At the same time,the plotline point out how hard it's to protect others when you need to be paranoid about everyone, and that many people hate/dislike you for it. People also have habit to forget those that give their life to save and protect others, when they are not in distress. Personally I find this episode did bring out both side quite nicely. The whole plot is quite "normal" in Castle. A fine plot with twist. Because this one is without the normal "hei,look, a arabic man, must be the terrorist" flavor, I give this a plus 8.5. Spoilers:
The dying by freezing was quite ok, but not as good as it could have been. But I did like the fact before Castle fall in to unconsciousness, Beckett was trying to say "I love you". And he wake up with "Biker boy" ogle at him XD. I find it quite funny.