Every year, Wang Ling suffers a run of bad luck around her birthday. As her twentieth birthday approaches, her nightmares begin coming true one after another. She dreams that someone with eerie green eyes pushes her down a flight of stairs; the next day, her roommate Chao Xin falls down the stairs. While playing cards, she keeps drawing the Three of Hearts, until a bizarre human figure appears on the card. She recalls that she once stole vegetables from an experimental field and accidentally pulled up a "human head," drawing the attention of a vengeful spirit. On her birthday night, the spirit takes control of her roommates and makes them attack one another. Armed with the Three of Hearts she secretly kept, Wang Ling defeats the spirit in a card game. When she wakes, her roommates are safe and sound. But inside the gift box they prepared for her birthday, another Three of Hearts still lies, a sign that the danger has not passed.
