The story is set "once, long ago" in a world of unicorns, princesses, fairies, and demons. Cruise plays Jack O' The Green, a woodland dweller who takes Princess Lily (Sara) to see the last of the living unicorns. But temptation and fate cause the world to freeze over when the male unicorn is seriously wounded and its horn broken off and stolen, and the female unicorn and Lily are kidnapped by evil goblins. Ultimately, it is Jack (with the help of a group of fairies and Elves) who must save Lily from the demonic, Satan-like Lord of Darkness (Curry), who wants to take Lily as his bride.