When the Last Unicorn Amalthea (Mia Farrow) realizes that she is the last, she is determined to find out what has happened to the rest of her kind. When she discovers that they have been herded to the ends of the earth by a mysterious creature known as Red Bull, she embarks on a journey to try and help them. Along the way she meets up with both friends such, as Shmendrick (Alan Arkin) and Molly Grue (Tammy Grimes), who aid her in her quest, and enemies like Mommy Fortuna (Angela Lansbury) and King Haggard (Christopher Lee) who attempt to harm her. After spending some time in human form to avoid the same fate as the other unicorns, she may have lost the spark of her quest. However, Prince Lir (Jeff Bridges), the son of King Haggard, helps rekindle the flame of her quest before it is too late.