Byeong-gu, a conspiracy theorist obsessed with aliens, believes that
extraterrestrials from "
Andromeda PK 45" are preparing to
invade Earth and that he must prevent their plot. With the help of Su-ni, his childlike
circus performer girlfriend, he kidnaps Kang Man-shik, a pharmaceutical executive who he believes to be an alien commander who can contact the Andromedan prince during a
lunar eclipse that is due to occur soon. Byeong-gu imprisons Kang in his basement and shaves his head to prevent him from sending a
telepathic distress signal to the Andromedans. Kang is subjected to various tests which include scrubbing him with a Korean liquid painkiller and an “
Italy towel” used by
ttaemiris. It is revealed that Kang’s company poisoned Byeong-gu’s mother during a drug trial, linking Byeong-gu’s
paranoia to personal tragedy. When a detective arrives to investigate Kang’s disappearance, Byeong-gu hides the evidence, but the officer later discovers human remains. He attempts to summon police backup, but is found and killed by Byeong-gu. Byeong-gu then crucifies Kang and breaks his leg after he attempts to escape. Kang convinces him that a bottle of
benzene in his car is an antidote for his comatose mother, and Byeong-gu takes it to her and makes her drink it, killing her. Meanwhile, Kang frees himself and uncovers his captor’s grisly research: bloodstained notebooks, jars of human organs, and photographs of victims. Reading through Byeong-gu’s journals, Kang learns of the man’s brutal upbringing: an abusive father, violent school years, his mother’s poisoning, and his lover’s death during a protest. The murdered detective’s partner locates the hideout before Byeong-gu returns. He captures both men, prompting Kang to claim that he is truly an alien. He says that the Andromedan race once tried to save humanity by altering human DNA. He promises to contact the alien prince at his company’s factory. At the factory, Kang activates a robotic arm that kills Su-ni and overpowers Byeong-gu. The police arrive and shoot Byeong-gu, who dies wondering who will save the Earth in his stead. Aliens appear and retrieve Kang, who is revealed as their king. Disillusioned by humanity, he declares Earth a failed experiment and obliterates it. The credits show a video diary from Byeong-gu’s life, highlighting fleeting moments of happiness with his parents and Su-ni. ==Cast==