Harry is a retired teacher in his 70s living in the Upper West Side of New York City where his late wife and he raised his children--where he's lived all his life. When the building he lives in is torn down to make way for a parking garage, Harry and his beloved cat Tonto begin a journey across the United States, visiting his children, seeing a world he never seemed to have the time to see before, making new friends, and saying goodbye to old friends.

This wacky prequel to the 1994 blockbuster goes back to the lame-brained Harry and Lloyd's days as classmates at a Rhode Island high school, where the unprincipled principal puts the pair in remedial courses as part of a scheme to fleece the school.