[6][7] The film features a clash between exiled prince Lee Chung (Hyun Bin) and the Joseon minister of War Kim Ja-joon (Jang Dong-gun) with the backdrop of a spreading zombie plague.

His son, Crown Prince Lee Young, plots to buy European arquebuses to drive away the Qing and at the same time removing his weak-willed father.

The crown prince comes to his father and begs him to consider his proposal to oppose the Qing, as they now have firearms, but the impotent and stubborn king refuses to listen to his son.

The vampires crave human meat and blood, are attracted by sounds, repelled by sunlight, and are stopped by decapitation or piercing of the heart, as well as separation of spinal vertebrae; conventional methods of killing are inconsistent.

The crown prince left a request that his wife Gyeong-bin and unborn child be raised by his younger brother Lee Chung in China for their safety.

Lee Chung and Hak-Su are assisted by local partisans, including Park Eul-ryoung, former lieutenant to the crown prince, and archer Deok-hee.

Paranoid, the king initially agrees as long Lee Chung does not want the throne, but the ministers instigate him to rescind the order, claiming no vampire outbreak, only a civil rebellion.

Lee Chung continues the plan, battling a horde of vampires and Kim, and scatters oil on the floor of the palace.

[19] Shim Sun-ah from Yonhap News Agency gave a mixed review and wrote, "Rampant has a promising premise, but it is a bland film that is marred by a predictable plot and cardboard characters.

"[20] Park Jin-hae from The Korea Times also gave a mixed review and wrote, "Hyun's skillful action scenes with a long sword, almost singlehandedly defeating zombies endlessly swarming from all directions, are entertaining.

"[21] The film recorded 156,644 admissions with US$1.1 million gross on its opening day, taking the box office lead from Dark Figure of Crime.