 A cynical young American, Thomas Doubting, (Jamie Walters), is given a magical amulet which takes him on a mysterious journey to the island of Sinmouth. The eccentric locals (including Joss Ackland, John Inman, Brian Blessed and Richard O Brien) believe he is the lost legend of "Mumbo Jumbo" - an entity who will restore their fortunes and rescue the beautiful Princess Vanilla (Melinda Messinger).