On a trip to Dublin to celebrate St. Patrick's Day, four college friends are lured to an abandoned tavern by a mysterious Irishman named O'Reilly. After agreeing to stay the night, the four young women learn that the tavern is also home to a hideous undead killer, Darragh O'Donoghue, who stalks the corridors with his rusty scythe, seeking bloody revenge for a tragedy that occurred two centuries before.