Cassidy joined the cast of "Smallville", a television show based on the DC Comics' superhero Superman, in the series' seventh season, starring as the new editor of the Daily Planet, Grant Gabriel, a love interest of Lois Lane. In truth, he was Julian Luthor, the cloned and aged brother of Lex. In the episode "Persona," Cassidy's character was shot dead, marking the end of his character's saga. Cassidy later returned to the Superman franchise portraying Jimmy Olsen in the 2016 film "".