Henry Gamble's Birthday Party takes place over 24 hours at the birthday pool party of 17-year-old preacher's kid Henry Gamble. The party guests include adults and teenagers from his church, as well as Henry's "secular" friends, including the closeted young Logan, who has eyes for Henry.

High school athlete Cyd Loughlin lives alone with her depressive father in South Carolina, perpetually longing to get away from it all. When her aunt, famous novelist Miranda Ruth, agrees to host her for a few weeks during the summer, Cyd jumps at the opportunity. While there, she falls for a girl in the neighborhood, even as she and her aunt gently challenge each other in the realms of sex and spirit.