Superman discovers a rocket ship which has landed near Metropolis. However, when he arrives, he discovers a Kryptonian girl inside, who's already dressed in a costume similar to his! She tells her story, revealing that she is the daughter of Zor-El and Alura, from Argo City, which survived the initial destruction of Krypton but which later succumbed to Kryptonite poisoning, forcing her parents to send her to Earth.