After one of Zigzoo's magical inventions spectacularly fails, he decides to quit inventing forever. Trying to encourage him to invent again by making up silly problems for him to solve, Twigs inadvertently causes a disaster that threatens all of Treetopolis and only Zigzoo can fix it. Tom and his friends have to convince Zigzoo to return to inventing before disaster strikes, but the day can only be saved with Big World Magic help from the audience.