A well written script that for once leaves you with the who dun'it until the very end of the story. You have all the pieces, but just not enough to put it all together.
An interesting cast of characters starting with Mistress Irena played by the sultry Dina Meyer of Birds of Prey fame among other TV shows and movies. There is the first year intern doctor fiancee, the mistresses at the "dungeon" she worked at, her roommate, her customers, and her fellow PhD candidates that were all viable suspects.
They gave some subtle hints from her research a little early in the episode that unless you were really paying attention it might have gone by too fast. A Destructive relationship she described which she was in that was very close.
Castle spends a lot of time being mesmerized by not only Lady Irena, but some of the thoughts that started running through his head about Beckett. Also his daughter is trying out for the cheer leading squad which seems to be causing him pain no end.
We finally get to meet Detective Ryan's girlfriend Danielle who has some very kind things to say about everyone and Esposito and Castle are a little jealous.
A well written plot, a well acted episode, and another winner for Castle. Even though it has not officially been renewed I have to think that ABC can't pull a new show out that is going to out perform this one. We'll see how long it takes them to announce it. Maybe they are waiting for FlashForward or V to fail first which would seem much more likely. Thanks for reading...