In Lapa, Rio de Janeiro, the idle aspirant writer Zeca has been living with Arts Professor Júlia for five years. He is stuck on page 50 of his novel for a long time and Zeca claims lack of inspiration to conclude the plot. He leads a comfortable life from inheritance left by his mother and administrated by his father Humberto. When Zeca sees Júlia alone with her best friend Carol in his flat, he believes that they are having a love affair and becomes obsessed with Carol, following her. Júlia travels to São Paulo with work giving Zeca the perfect opportunity to have an affair with Carol. So begins his complicated life: while Júlia works and studies for her doctorate, Zeca has sex with Carol during the days and with Júlia during the nights. Zeca plots a scheme to stay with either Carol or Júlia but his plan does not go as he hoped.