Matthew is bored staying at his Grandmother's during the school summer holidays. He is convinced he can hear music coming from inside the Grandfather Clock. When he opens the panel and squeezes inside, he steps into another dimension. In the fantasy world he meets Phineas, an old man who directs his adventure. Matthew meets unusual characters like Popcorn, the dragon and Mr Tumblederry, a turnabout. He makes new friends Indi and Rascal. They enter the magical world of Illusion where they experience their choice of adventures. They have an exciting visit to an Apache Indian reservation. Then Indi sets Matthew a challenge. He has to propose the next expedition. Matthew decides they should have a pirate adventure. They become pirates and they are given a treasure map. The boys try to keep one step ahead of the real pirates but Blackbeard and his crew are close behind. As a contrast in his own world Matthew works on a farm. He gets upset when he hears about the piglets going to market. He rescues his favourite piglet. Grandmother's house has to be sold. Matthew is worried about the future of the Grandfather Clock. Phineas reassures him that the clock will find its own destiny.
