 Mercedes supports John Paul when he reveals that he was raped by one of his students, Finn O'Connor (Keith Rice), and Mercedes starts feuding with Finn's stepmother Diane O'Connor (Alex Fletcher), who protests Finn's innocence.Mercedes, Myra, Nana and Carmel publicly embarrass Diane and support John Paul in court at Finn's trial, when Finn protests his innocence and lies, claiming that John Paul molested him, but Finn is found guilty for the rape and sent to prison.When Carmel is killed in a train crash, Mercedes clashes with Theresa and blames her for having ruined Carmel's life while she was alive.