LSD almost ruins the life of a former actress and her stepdaughter.

Broadway actress Adriana Roman abandons her career to become the wife of tycoon Charles Winthrop. His daughter, Lisa, disapproves of the marriage and begins to associate with a group of abandoned, drug-using hippies. Winthrop drowns trying to save Adriana when his yacht is wrecked in a storm, and Adriana, rescued by fishermen, becomes Lisa's guardian. Lisa's inheritance is placed in Adriana's trust, subject to her approval of Lisa's marriage. The resentful stepdaughter and her greedy boyfriend, Johnny Allen, a medical student and frequent LSD user, mix an LSD cube with Adriana's sedatives when she fails to approve their marriage. Adriana eventually goes insane, and, suffering from amnesia, she is placed in a mental hospital. Playwright-director Frederick Lansdale, a close friend of Adriana's, suspects that something is amiss. Lisa discovers Johnny's infidelity on their wedding night, and, realizing that he courted her only for her fortune, she confesses the entire affair to Frederick. Frederick writes a play based on Adriana's traumatic experiences and persuades her to act in it. On opening night, Adriana regains her memory, recognizing her nightmares as instigated by Johnny to force her to suicide. The fully recovered Adriana returns home to the repentant Lisa and the loving Frederick, while Johnny is destroyed by drugs.