Going where no killer Leprechaun has gone before, in his quest to rule the Universe, the Leprechaun has kidnapped a gold-digging alien princess who he plans to marry. Then, with the combination of her royal title and his gold he will be the Galaxy's most powerful being and no one will be able to overthrow him! However, the Leprechaun's plans don't allow for a platoon of invading marines sent to rescue the princess! Stowing away on the mariners spaceship, he discovers the princess is being held captive by a sinister half-human, half-computer doctor, who plans to use her DNA to restore his human body to its former self. When the Leprechaun learns of the doctor's plans, his revenge sees the crew fighting not just the cunning and clever Leprechaun, but also a gigantic blood-sucking creature, all whilst disarming the spaceship's self-destruct timer which is set to explode - all the ingredients for a space ride from Hell!