Once upon a time, when everyone in the city was getting ready for Christmas, someone suddenly noticed that all the children had disappeared without trace!From under the noses of their hypnotised parents all the children in Magnapolis have been lured away by the siren song of a mysterious character known as the Puppeteer. With the aid of his gang of sinister automata, he has decided to avenge himself on the city which once rejected him by taking from him what he most appreciated – little children!Neither the police nor Alan can find any clues. Even Monty and Gina have inexplicably disappeared, leaving our invisible hero to solve this mystery on his own. Clearly, a difficult Christmas lies in store for the Invisible Man.