Dr. Penny Barber, a therapist with a hidden agenda, manipulates her patient, Elias Cash, into having sex with his stepsister, Penelope Woods, as 'therapy.' She believes their taboo relationship will bring them closer. Dressed in thigh-high boots and a revealing outfit, Penny conducts a peculiar medical interview, talking Elias through his desires while Penelope listens, growing increasingly aroused. Elias, initially hesitant, finds himself drawn to his stepsister's curves and the doctor's dominant presence.