Warning: Spoiler Alert
Of course Castle survived everything that happened to him, cuz the writers weren't going to be stupid enough to kill off the title character of their money train. That would just be stupid. At a certain point, it just comes off as silly that they would even think that there would be any tension when they put Castle or Beckett in peril, since I don't see how anyone would actually think that they would write either of those characters off the show. That would just be silliness on their part. No lie. The only way that there would be any tension with that sort of thing is if they decided that they wanted to do something with one of the tertiary characters, since those are the only ones that are really in any kind of danger (like when they killed off Montgomery). I would say that the secondary characters might be in a bit of peril as well, but the only one of those that was really in any danger was when they went all Taken with Alexis, and she was actually fine (there was no way that they were going to actually get rid of our favorite ginger pixie).
Again, there was not enough of the boys in this episode, and it was even worse than it was in the last one (since they were really on there for like 30 seconds). But since it seems like Beckett seems to be rethinking her decision to move to DC, it looks like she might be going back to the NYPD pretty soon ... which would make me all kinds of happy. This show is about NYPD Homicide, bitches. It's not about DC or the Feds.
I didn't like the fact that Castle or Beckett lied to everybody about what was wrong with Castle. I know that he didn't want to worry them, and she wanted to back him up ... but they were all genuinely worried about Castle (cuz they care about the big idiot), so it made the lying seem that much more like it was a betrayal of their trust (at least from where I am sitting anyway). It may have only made everyone worry even more than what they already were, but at least they would have been prepared for if something horrible happened, instead of suddenly getting a call to tell them that Castle had died and having it drop out of the air onto their heads without them being able to be ready for it ... but that may come a bit from the fact that my gram (who I was really close to) died really unexpectedly, and I think that I would have preferred being able to at least see it coming (like my mom had cancer, and while it didn't make it not suck when she died, at least we were kind of prepared for the possibility, since we knew it was there).
But so much for giving us a new big bad for the future (since the gang has either taken out everyone that they can, or the one that they can't, they've gotten as close to him as they possibly can). I'd like it if there was an ongoing mystery going on in the background that the gang was trying to deal with, but I'm not sure that we're going to get much on that front anymore. Seems like there's only so much that the writers can do with the ultimate Big Bad that was responsible for Beckett's mom's death without making him seem overplayed and not so mythic.