Su-hyeon, a patient with terminal cancer, gets a wig as a present from her sister, Ji-hyeon. Strange things happen as Su-hyeon wears the wig and horror starts to sweep over Ji-hyeon as she watches her sister getting slowly possessed.
A wig is a head covering made from human or animal hair, or a synthetic imitation thereof. The word is short for "periwig". Wigs may be worn to disguise baldness, to alter the wearer's appearance, or as part of certain professional uniforms.