"The Effect of Gamma Rays on Man-in-the-Moon Marigolds" is a play written by Paul Zindel that explores the struggles of a dysfunctional family. The story centers around Beatrice, a troubled mother, and her two daughters, Tillie and Ruth. Beatrice's harsh demeanor and neglectful parenting create a challenging environment for her daughters, particularly for Tillie, who is passionate about science. The play highlights themes of isolation, resilience, and the quest for identity. Tillie's science project, which involves exposing marigold seeds to gamma rays, serves as a metaphor for her desire to rise above her circumstances and find beauty in a harsh world. The narrative ultimately examines the impact of familial relationships on personal growth.