During a perilous 24-hour mission on the moon, space explorers try to retrieve samples from an abandoned research facility steeped in classified secrets.
Director Choi's briefing about the mission leaves Song Jian displeased. Reaching the research station alone proves no easy feat for the crew.
The crew's initial findings are at odds with their knowledge of the research station. Split into threes, the members set out to look for the sample.
Jian's body cam captures a startling moment of life and death. Submerged in sweat, Gong Soochan shows worrisome signs of an unusual infection.
Han Yunjae updates the director and gets access to a restricted area. The crew learns of the sample's powers and the true motive behind their mission.
Recalling her sister's encrypted message, Jian searches the database for Luna. A young intruder and a double-crosser emerge from the shadows.
E2, Ryu Taesuk and the samples go missing. Seeing a familiar name on the intruder, Jian follows her down the vents for answers.
Jian opens a hard drive that chronicles Song Wonkyung's life and work on the station. Meanwhile, others uncover the remains of the experiment.
Racing against time as the research station falls under destruction, the surviving crew members decide on the fate of the mission — and their own.