After Anna (Isabelle Adjani) reveals to her husband, Mark (Sam Neill), that she is having an affair, she leaves him and their son. Mark is devastated, and seeks out Heinrich (Heinz Bennent), the man who cuckolded him, only to receive a beating. After a series of violent confrontations between Mark and Anna, Mark hires a private investigator to follow her. Anna descends into madness, and it's soon clear that she is hiding a much bigger secret -- one that is both inexplicable and shocking.