There aren't that many books at this point. There are only 3, including the one mentioned after this episode that's just been released, and a graphic novel for "Derrick Storm" who is the main character in Castle's previous series as mentioned in the show. Never read the graphic novel and I just bought the newest book. The books have been good reads so far, they're nothing ground breaking and read like an episode of the show. There enjoyable for a quick and easy read so I'd recommend them. If you're looking for a really dark, deep murder/mystery read, you won't find them in these books though.
I enjoyed the episode, I felt it was a good opening episode for this year after the cliffhanger from last year. I also like how they handled the whole "I Love You" revelation from Castle at the end of last years finale. It would've been such a cop out for her to actually forget it, or for them to start a relationship at this point with everything going on, it's a brave choice, one that I'm sure will have consequences later on.
I also like the whole Kate seeing a psychiatrist angle they're going with. With everything that's happened to her, and where things are still at, I couldn't begin to understand what she's going through and I'm glad she's getting help. It certainly helps that it's Michael Dorn too, I hope he sticks around for a while, I always liked him. I guess that's at least two former Star Trek alumni that's been in this show now, plus someone who was in a Firefly episode.
Rick is going down a dangerous road here with him leading Kate away from her mothers case in an attempt to protect her. I get the feeling he's really going to pay for it in the long run, not only with Kate, but with his mother and daughter as well. Can't wait to find out who this new, secret guy is, and what his role in the whole thing is. I have my suspicions that the mayor is involved in this as well.
I think my only problem with the episode was the actual murder/mystery itself. Of course, that's never been a strong point for the show, or it's main focus. The show has always been about the characters and their interaction with each other but, come on. You mean to tell me no one bothered to search the chicks room before Castle showed up? I mean, the sheets and everything had been removed from the bed, probably by forensics, and no one notice the lack of a blood stain under the bed in the shape of a body, and fingerprints on the bed frame? That was a stretch imo.
Anyway, looking forward to the season and to seeing where it all leads to. Hopefully, they can continue and improve upon where the shows been so far.