Parasites fall from space and take over human bodies by controlling their brains. Jung Soo In survives a failed takeover and begins an uneasy coexistence with the parasite in her hand. Seol Kang Woo searches for his missing sister, while Choi Jun Kyung, leader of the task force "The Grey," is determined to eradicate the parasites after losing her husband to them.
(Source: MyDramaList)
~~ Adapted from the manga series "Kiseiju" (寄生獣) by Iwaaki Hitoshi (岩明均).
