In the midst of a summer heat wave, New Yorker Richard Sherman (Tom Ewell) ships his wife, Helen (Evelyn Keyes), and their son off to Maine for vacation. Left alone to work back in Manhattan, Richard encounters a gorgeous blonde model (Marilyn Monroe) who has moved into the apartment upstairs, and becomes immediately infatuated. While pondering infidelity, Richard dreams of his beautiful new neighbor — but will his fantasies about her become a reality?