Peter (Oakes Fegley) is thrilled that his Grandpa (Robert DeNiro) is coming to live with his family. That is, until Grandpa moves into Peter's room, forcing him upstairs into the creepy attic. Although he loves his Grandpa, Peter wants his room back, so he has no choice... but to declare war. With the help of his friends, Peter devises outrageous plans to make Grandpa surrender the room, but Grandpa is tougher than he looks and conjures his own plans to get even. Starring an incredible cast, including Robert DeNiro, Christopher Walken and Uma Thurman, 'The War With Grandpa' is a hilarious family comedy about getting your own back!