It is based on the 1981 children's book of the same name by Barbara Brooks Wallace and originally aired in two parts on ABC Weekend Special series on January 16 and 23, 1982.
[3] Rupert Brown and Amelia Daley receive a mysterious package from a spooky old crone: a ship inside a bottle with a miniature man aboard.
Traveling back in time on her broomstick, Miss Switch and Rupert eventually find Amelia on Mordo's pirate ship, where the warlock is about to administer his evil potion to mayor Daley.
Upon their return to the present, Amelia and Rupert learn from Miss Switch's magic encyclopedia that the real power behind this diabolical plot is Saturna, meddling from afar on the Island of Fire and Ice.
An expanded rescue mission unfolds, culminating with the troll Thaddeus drinking the antidote, transforming back into Mayor Daley, who is in fact Amelia's 300-years-removed grandfather.