When Mr. Simmons, Arnold's teacher, announces that next weekend is the annual Parents Day Tournament Weekend, all of the fourth-grade kids are excited. Everyone except Arnold, that is. He doesn't have parents, and even though Grandma and Grandpa are ready to compete in the tournament with him, Arnold feels too sad to compete. What's more, Arnold doesn't know what really happened to his mom and dad. Will Grandpa tell Arnold the real story of what happened to his parents? Find out in this heartwarming story.