Peter is thrilled that Grandpa Jack is coming to live with his family. That is, until Grandpa Jack moves right into Peter's room, forcing him upstairs, into the guestroom. Peter loves his grandpa, but he wants his room back. He has no choice but to declare war! With the help of his friends, Peter divises outrageous plans to make Grandpa Jack surrender the room. But, Grandpa Jack is tougher than he looks. Rather that give in, Grandpa Jack plans to get even. They used to be such great pals. Has their war gone too far? Well, both Peter and Grandpa Jack attack each and fight back. However, when it has gone too far, Peter gives in, because he feels bad for his grandpa. But, Grandpa Jack rebuilds the basement so that it can be his room. At the end, everyone is in their right positition and they are all happy!