Tracy Scoggins appeared as Cassandra in episodes
on Highlander:The Series.
Comes a Horsemen
Cassandra hears that the Four Horsemen are still alive after thousands of years and tries to track them down. She is filled with hate for all of them, even Methos, whom she may have loved at one time. She gets MacLeod to help her in her quest. He agrees even though it means losing a friendship with Methos. In this episode we discover that there is a lot more to Cassandra (and Methos for that matter) than what we learned so far. This is where we get a look into her past to discover who she is and how she came to be the way she is. This episode made Cassandra a more concrete addition to the Highlander family... even though she's not listed as one of the main characters. How many people think that should be changed?
Part 2 of the Horsemen episodes. In this one, more of Cassandra and Methos' past with the horsemen are revealed. She is captured by Kronos, Caspian, and Silas to be executed. Methos saves her in the end, but she still tries to take his head. Duncan prevents her from doing that. And she leaves. Although Duncan steps in at the end and stops Cassandra from taking Methos' head...I don't believe she'd have done it anyway. Sure Duncan has a lot of influence over his friends, but if someone was as vengeance-bent as Cassandra was made out to be even the mighty Macleod couldn't have stopped 'em. Which is why I believe that Cassandra still loved Methos' she only felt betrayed by him.