The notion that Luis would move on, let alone with her niece Fancy, caused a mental breakdown within Sheridan's mind; shunning Chris and his son, Sheridan began morphing into a full-fledged villainess, who was determined to destroy Luis and Fancy for falling in love. When Fancy was raped by her half-brother Vincent Clarkson, Sheridan destroyed evidence regarding the rape in order to make it appear Fancy was making up her claim of being sexually assaulted and later, testified against Luis, when he was put on trial for several murders Vincent had committed as the masked "blackmailer". While Fancy fought to clear Luis of the charges against him, Sheridan was willing to protect Vincent when she discovered that he was the masked blackmailer. Vincent nebulously agreed to get Luis released from death row if Sheridan murdered Theresa (who was standing in the way of Vincent's quest to have sex with his step-brother Ethan Crane-Winthrop), which Sheridan did. Electricuting Theresa (who survived ironically due to the timely intervention of her nemesis Gwen), Sheridan discovered that Vincent had no intention of honoring his vow to free Luis. Sheridan's response was to stay silent and protect Vincent, on the basis that she would rather have Luis be dead than with Fancy. Impressed by Sheridan's cold-blooded nature, Vincent agreed to help her find Pretty Crane, Fancy's evil younger sister. Sheridan convinces Pretty to tell Luis how Fancy had disfigured Pretty after a fight over a boy the two girls both loved. However, Fancy was able debunk Pretty's claims by revealing that Fancy disfigured Pretty in self-defense as far as the fact that Pretty was trying to murder Fancy during the fight and that the chemicals used to disfigure Pretty were used by Fancy in a desperate move to stop the murderous Pretty.