A television news reporter, Diana Stride (Raquel Welch), wants to discover the true identity of Superman and expose him to the public. Her first attempts are not much successful since Clark manages every time to appear in front of her as Superman, before she realizes who he really is. At the same time, Mr. X, a former member of Intergang, is about to testify against Intergang and one of its assassins. As it turns out, the assassin is Diana, who attempts to silence him before he does it. Superman gets into her way and she decides to kill him. She kisses Superman while wearing a kryptonite lipstick, something that makes Superman very sick since the kryptonite enters his body and spreads like a cancer. Before he is rushed to the hospital, Diana finds out that Clark Kent is Superman and makes a story about it on TV while Superman finds a way to "kill" the kryptonite that is inside him. Everyone is surprised when they hear the news about Superman's true identity and Clark organizes a press interview to prove that he is not Superman. With the help of his parents, they create an hologram of Superman that appears during the interview while Clark is also standing there, and Superman explains that Clark is his friend and he helps him by keeping his things at his house. After the press interview, Superman goes on to arrest Diana.