Awakened by a negligent sorcerer, Pernickety Boo, an erudite umbrella with untapped magical abilities, finds himself abandoned on the London Underground. Desperate for a loving owner, he crosses paths with young Sylvie Moonshine, who takes him in. However, others covet the magical umbrella, posing a threat to separate Pernickety from Sylvie unless he can outwit them.