Gurus in the late Goryeo dynasty try to obtain a fabled, holy sword, and humans in 2022 hunt down an alien prisoner that is locked in a human's body. The two parties cross paths when a time-traveling portal opens up.
Ryu Jun-yeol
Kim Woo-bin
Kim Tae-ri
So Ji-sub
Yum Jung-ah
Jo Woo-jin
Kim Eui-sung
Lee Ha-nee
Shin Jung-keun
Lee Si-hoon
Kim Dae-myung
Choi Yu-ri
Kim Ki-cheon
Yoon Byung-hee
Ji Gun-woo
Yoon Kyung-ho
Ok Ja-yeon
Lee Hyun-gul
Kim Hae-sook
Yoo Jae-myung
Jeon Yeo-been
Kim Min-seo
Lee Sun-hee
Baek Hyun-joo
Choi Kwang-je
Shim Dal-gi
Oh Chae-eun
Jang Jun-whee
Lee Dong-yong
Kim Jung-han
Kim Chan-hyung
Lee Dong-hee
Song Ji-hyuk