The Effect of Gamma Rays on Man-in-the-Moon Marigolds is a play written by Paul Zindel, a playwright and science teacher.
Directed by A. J. Antoon, the cast included Shelley Winters (Beatrice), Carol Kane (Tillie), Lolly Boroff (Janice Vickery), Isabella Hoopes (Nanny), and Lori Shelle (Ruth).
[5] The play revolves around a dysfunctional family consisting of single mother Beatrice and her two daughters, Ruth and Tillie, who try to cope with their abysmal status in life.
[6] Shy Matilda Hunsdorfer, nicknamed Tillie, prepares an experiment involving marigolds raised from seeds exposed to radioactivity for her science fair.
As the play progresses, the paths of the three characters diverge: Ruth has a nervous collapse while attempting to stand up to Beatrice, who, driven to the verge of insanity by her deep-seated enmity, impulsively kills the girls' pet rabbit Peter and wallows in her own perceived insignificance.