 It s the 21st century. A group of U.S. Marines battle in space to destroy a space monster, when they get in the way of the Leprechaun who is in space to marry a princess so he can become ruler of the planet Dominia. They think they have killed the Leprechaun - wrong. The Leprechaun goes on board their space station to find the princess they have taken from him, where he ll kill to get her back.