I'm crying again, Mum. I'm crying because I don't know how many letters I have to write to say goodbye to you. More than anything, I wish I knew. Seventeen-year-old Rhea Farrell has scars from a childhood accident in which she lost her arm. But she also carries scars that aren't so visible—the loss of a mother she hardly remembers, the impact of her father's drinking, and her confusion and pain around accepting her sexuality. When Rhea runs away, she turns to the person she's always wished she could confide in: her mother. And just like she used to do as a little girl, Rhea starts to write her letters—to tell her things she can't tell anyone else, to share her fears, to ask for help. Rhea's journey on the streets of New York brings her deeper into her mother's past, where she uncovers buried family secrets. And as she finds out more about the woman her mother truly was, Rhea also discovers just what kind of woman she wants to be.