When a juror dies during the high profile trial of a murdered socialite, Castle and Beckett discover that the juror wasn't really as perfect as he appeared to be.
Rigby finds an old tape with one of his former favorite songs on it, only to find that it's not as good as he remembers. Problem is, the song gets lodged in his brain and cannot stop humming or singing it so Mordecai tries various methods to get rid of it.