Excellent episode. Lots of twisty turns with several surprises in store. Often, I spot the villain too early in the episode, but not in this case.
I was sad that Cynthia's killer had to face a jury, because she tried to make restitution for so long, and it was self-defense, in part.
Favorite moment for me: Castle telling Lee Wax off for deliberately exposing the victim's identity and location just to get control to write a better book. Laughed when he said her actions weren't illegal, but slimy.