Middle-aged philosophy professor Marion Post (Gena Rowlands) would appear to have every advantage. After all, she has a rock-solid professional reputation, an equally secure marriage and enough spare cash to be able to rent a separate flat in which to write her latest book without interruption. But she is interrupted, thanks to an accident of ventilation, by the therapy sessions going on in the psychiatrist's office next door. Voyeuristically fascinated, Marion is particularly struck by the way that the unhappy experiences of his patient Hope (Mia Farrow) mirror her own, and realises that her life is nowhere near as materially and emotionally secure as she's been pretending. And when she decides to rely less on her beloved logic and reason and open herself up to dreams, imagination and passion, the scene is set for a life-changing transformation.