After this episode, Dax became my favorite character. Her having lived so many lives can make for a very interesting situation, which is exactly what this is! Dax is being put on trial for a murder which Curzon is accused of having done, but even when there is information to clear her name, Sisko is wondering why Jadzia won't talk as he investigates the years-old murder. The ending is quite shocking, but I won't give it away. The mystery is great and isn't hard to follow.
This episode kind of introduces Dax to us, explains a little more about Trill, and in my opinion is a really good episode.