In 2018, Leigh Harrison is fifty, divorced and raising two teenage girls. Absorbed by her work and her home, she doesn’t have time to think about the past. But when her mother has a stroke, she returns to her childhood home where the past opens before her. In June 1978, Leigh is ten years old, naive about life around her, friendships, sex, and death. She is obsessed with Shaun Cassidy. Her best friend, Sunny, is spoiled, bossy, and possessive of Leigh's friendship. Leigh's older brother, Pete, has leukemia and has been sick for three years. Since he is no longer receiving treatment, Leigh believes he is getting better. Leigh's parents are struggling with the emotional toll Pete's illness has placed on the family. And, on top of everything, her fifth-grade teacher seems bent on making life difficult for her and her classmates. Thoughts of family, friends, and experiences growing up allow Leigh to touch old grief as well as understanding her family and herself. Her memories are at once funny, nostalgic, painful, and ultimately heartbreaking. Under the Thumbnail Moon is about family, sorrow, self-discovery, and what truly matters in life.