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.

Pil-ju, a retired soldier of his 80s with dementia, goes in search of the people he believes to be responsible for the death of his family in the past. With 5 names tattooed on the fingers, and pieces of his collapsing memories, Pil-ju tracks down his targets and kills them one by one. A young innocent guy In-gyu unintentionally gets involved in his revenge, and eventually becomes the prime suspect of the murder that Pil-ju committed. To prove his innocence, and to stop this old man's rush, In-gyu can't help but accompanying Pil-ju's revenge journey. Yet, Pil-ju's plan comes closer to an end leaving one last person to execute... Before his memory is completely gone, can Pil-ju get his lifetime revenge done?

Pil-ju, a retired soldier of his 80s with dementia, goes in search of the people he believes to be responsible for the death of his family in the past. With 5 names tattooed on the fingers, and pieces of his collapsing memories, Pil-ju tracks down his targets and kills them one by one. A young innocent guy In-gyu unintentionally gets involved in his revenge, and eventually becomes the prime suspect of the murder that Pil-ju committed. To prove his innocence, and to stop this old man's rush, In-gyu can't help but accompanying Pil-ju's revenge journey. Yet, Pil-ju's plan comes closer to an end leaving one last person to execute... Before his memory is completely gone, can Pil-ju get his lifetime revenge done?