[Spoiler (click to open)]
It didn't actually keep up the crazy shippy focus all the way through like it could have - which worked much better in the end. Because who could resist the switch from angst to swooning, to pure bedroom farce, to piling on the angst again until something had to break. And it broke beautifully, Castle propping Beckett up until she could see a way to take back control of the situation.
Because storming a senator's fundraiser, complete with gun for a spot of bluffing/blackmail, was an awesome way of getting that done. Neatly enough, it fixes Kate's whole being targeted for assassination problem too (even if, amusingly, the boys all assumed she was actually crazy enough to go kill a senator right up until the last minute?! Not that it's totally outside her skill-set/stress level, but a little faith wouldn't go astray guys, surely?)
Not sure what was my favourite part - Martha storming the bedroom and Kate spitting feathers (and throwing pillows) in the closet? Hungover and miserable Alexis inadvertently curtailing the morning after scene everyone had been waiting months to see, and all Castle could think of was trying to deprive her of aspirin while Kate sneaked out...
Also loved Javi all the way through being awesome, and Ryan being plucky and put upon and also awesome. Everybody got to save the day in this one at various points (except Lanie was mysteriously missing, and Martha and Alexis were reduced to comedy cameos, but hey). The evil senator's monologue was seriously creepy, and Kate's response was totally spot on. Frankly she showed a hell of a lot of self control not shooting him just for subjecting her to that...
Best of all, Castle and Beckett are just... together. Not really much angst at all, apart from the whole trying to keep it secret thing (that attempt will go FABULOUSLY guys. No really.). They had one 'so this is serious, right?' conversation, and then it just.. is. And Beckett watching Castle sleep while she got ready to go on her mission was heartrending, even if it did end well (the lift scene!) We got the initial 'eep' scenes, so the audience is happy, and now they get to have the perfect set-up for the summer off gallivanting together (details of which can probably be found in a thousand fics online right now...) and we'll see them again when Beckett comes back to work - because procedurals have to, er, be procedurals, right?
I keep comparing it with Bones, purely because they have such similar trajectories. And even though Bones was winning me back over towards the end of the series, it's not the show it was. Booth and Brennan still feel like they don't quite fit - and frankly, overprotective!Booth made me want to throw things at the TV. I keep watching because it's not completely lost it - not in the sense that I now pretend House ended at season 7, because it jumped the shark so completely at that point that I had no interest in anything after that.
But Castle was a masterclass in how to do it almost perfectly - they could have loaded on the shippy stuff a tad more; I wouldn't have complained - but oddly enough it worked like this, as it wasn't the main plot, not when everyone's focus had to be on finding the assassin and keeping anyone from trying to kill Kate yet again. And Kate solved her own problem in the end, and didn't have to be rescued, and got her job back, and walked off into the sunset (temporarily) with her guy for a well-earned break? It's all rather lovely, and probably definitely can't last. But it was so much fun to watch.