Bored with their marriage, the architect Marcelo proposes his wife Ana, a relation to three, with another sexual partner. The woman accepts, but the situation escapes from Marcelo's control because Ana engages lovingly with each other, and Marcelo no longer fits in the triangle proposed.
A model is found dead in the bathtub of her own mansion. A policeman tries to investigate, inquiring the rich and powerful men who knew her.
