Young Luke and his grandmother, on vacation in England, have just checked into a hotel. Also in the premises is the Royal Society for the Prevention of Cruelty to Children, a false moniker that hides the fact that the organization's members are really evil-minded, mask-wearing, child-hating witches. And they have all gathered to discuss a most fiendish plot: to turn all children into mice, by feeding them poisonous chocolate. Luke overhears the heinous plans when he eavesdrops on the women, but unfortunately they capture him and turn him into a mouse. Unlucky Luke must scurry back up to his room -- without getting killed -- and alert his grandmother of the witches' intentions, before it's too late. Then, the neophyte rodent must find a way to become human again.