The dramatic music score at the end of the episode where Krystle and Rita are fighting is pretty much the same as in the season three finale when the cabin is on fire.
This episode features the notorious fight between Krystle and her lookalike, Rita, both played by Linda Evans. Well, not entirely, as it is more than obvious in the ensuing tussle that it is two stuntmen dressed up like Krystle and Rita, complete with unconvincing wigs.
There is an episode in Season 4 with the same title.