Set in 2030, when the manned lunar exploration project has progressed considerably. Astronaut Hwang Seon-woo, was stranded on the moon alone in space beyond 384,000 km due to an accident, while Kim Jae-guk, the former head of the space center desperately trying to save him. On the other hand, Moon Young, general director of the National Aeronautics and Space Administration space station, has a hidden secret.