Une famille américaine, en voyage en Irlande à la recherche de leurs racines, tombent sur une horde d'enfants mutants assoiffés de sang.

It's 1967 and British pop sensations Norman's Normans have accidentally blasted off a rocket from the British Space Agency and landed on a planet of all women. When the princess falls for lead singer Norman, the queen imprisons the British invaders. Can they use their catchy rhythms to win over the girls of Hormone and help them make peace with the neighboring planet of men, all the while finding a way back home to Earth?