Tanner and Louise have a 63 year age difference and pretty opposite personalities: Tanner is a former college athlete, hitting what she thinks is rock bottom after dropping out. Louise is the eccentric elderly lady she gets hired to take care of. But in Colleen Oakley's new novel, The Mostly True Story of Tanner and Louise, the two women forge an unlikely friendship when Louise's past forces them to hit the road. As the author tells NPR's Mary Louise Kelly, the story is equal parts inspired by Thelma and Louise and by her own friendship with her grandmother.