In war-torn 14th-century Japan, an old woman whose son has gone off to war lives with her daughter-in-law in the tall reeds of a swamp. In the wild, lonely landscape, the two women survive by killing wayward samurai, dumping the bodies, and trading the armor and weapons for food. When their neighbor Hachi returns from battle, he reports that the old woman’s son is dead. He joins their samurai-slaying schemes while seducing the now-widowed young woman. Furious that her daughter-in-law sneaks off every night to sleep with Hachi, the old woman plots to terrorize the two by donning a demon mask acquired from a disfigured samurai general she has killed. She soon finds, however, that the mask is no mere toy…. A chilling, atmospheric classic of the samurai and horror film genres.