Castle: "I prefer slippery to sticky"

This week's Castle episode was filled with sexual innuendos, surprisingly mostly coming from Beckett, but it also was an episode that continued to surprise me. I love that up until the very last second of every episode you don't know who the killer is. And when they finally tell you, it is in no way someone you suspected. In a way, this is something a lot of crime/police shows do, but for some reason on Castle I think it is more appreciated. In your mind you are considering the four or five possible killers, but at the last second Castle has an epiphany and the killer is revealed as someone out of the blue. But then it all makes sense. This keeps the show fresh and helps it not become stale. Thanks, Castle writers, for continuing to hold my interest and for keeping me on the edge of my seat.