In this animated musical, the villainous King Haggard (voiced by Christopher Lee) plots to destroy all the world's unicorns. When a young unicorn (Mia Farrow) learns that she's in danger and may soon be the last of her kind, she leaves the safety of her protected forest and enlists the help of Schmendrick (Alan Arkin), a gentle but clumsy sorcerer. Together, they embark on a long and dangerous journey with one goal: to defeat Haggard and save the unicorns from extinction.