Day in and day out, lovers Cynthia and Evelyn enact an elaborate sadomasochistic fantasy as mistress and maid. But as their ritual of domination and submission begins to turn stale, Cynthia yearns for something more conventional, while Evelyn tries to push their taboos even further.
The newly married Elizabeth arrives with her new husband, the scientist Henry, at a magnificent house. He tells her that she can do there anything she pleases, except to enter a certain closed room.
