The case was a little weird, especially with the ending but I liked the character moments in the episode - like the handshake of Castle and Beckett, so adorable! Plus "The butler did it" had me cracking up :).
Loved that Martha knew immediately about Castle and Beckett and that Castle told Alexis. Castle dealing with Alexis moving out was a little sad and sweet as was Martha's offer of staying so that Castle won't be alone. Wonderful episode.