Hugh Klein was an astronaut from the Mission Apollo XXV than reached the moon. In the moon, Hugh discovered an ancient Roman temple with a baby girl inside. There the Hundred made themselves manifest and explained the situation. Hugh returned to Earth with the infant girl, and he and his wife Jenny, were allowed to adopt and raise the infant, whom they named Laura.
Years later Hugh revealed the truth to Laura and accompained her to the moon where the Hundred revealed the mission for the girl and how she had to opposed to the Centurian. As time went on, Hugh saw how his daughter, as Moon Maiden, became member of the justice League and friends with the world’s greatest heroes.
However when the Centurian attacked, he used a weapon called the erasure weapon, and using it caused to erase people from time and space, in a domino effect. In an act of heroic self-sacrifice, Moon Maiden, levitated herself and the Centurian high into the sky, and there destroyed his weapon, causing a great explosion and removing the two of them from history. Only Hugh Klein was able to recall his daughter and the events that had occurred. In this new reality he never was an astronaut.
Moon Maiden eventually returned along with the Centurian as his captive. Hugh was able to reawaken the memories of Laura in members of the Justice League, and together they were able to free her from the Centurian’s thrall and stop his plans of conquest. Afterward, he was reunited again with his lost daughter.