I loved this episode
First Castle is jalous of the actrice cause she's more famous and she doesn't know who he is etc, while Beckett is friendly to her (more then to him in the beginning) and doesn't involve Castle as much in the investigation.
but in the end it's the other way around, with Beckett who is freaked out about the actress because she is getting in her head etc and Castle who likes her more and more
But I just love how Becket thinks that Castle and Natalie slept together till Natalie askes if Castle is gay
And Ryan with his proposal and his list was funny too :)