Dynasty - Season 4 Episode 27 : The Nightmare 1989

Alexis suffers recurring nightmares about Mark's death. Kirby again tries to kill Alexis. When she is unable to pull the trigger, Alexis offers to remain silent in exchange for Kirby's agreement to leave Adam. The truth behind the attempt to unhinge Claudia is revealed. Sammy Jo seduced Hess into handling it, and has returned to him now to solicit his help in regaining her child. In preparation for the wedding, Alexis and Krystle visit the same beauty salon. The two women exchange words, and a mud-slinging melee ensues. While dressing for the wedding, Fallon is gripped by a seizure. She drives off as the ceremony is about to take place. The police arrive and arrest Alexis for the murder of Mark Jennings.