Mater is a film about the struggle between love and law; about social differences and distances that these generate. And about love, that crosses all, allows all: both good and evil.

Are we what others see, or are we what we allow others to see? Most likely it is the view of others which delimits our own identity, as a young divorced mother named Julieta convinces herself. This evening is like any other: her two young sons are roughhousing in their cramped apartment. They whoop and shout while their mother makes desperately futile attempts at the computer to concentrate on writing a report for work. Feeling intense pressure, Julieta tries to quiet the conflict but finds it difficult without a partner to help. The tense situation changes unexpectedly when her two-year-old falls and hurts himself. In this story of a mother suspected of hurting her own child, the movie investigates themes of motherhood, guilt, duty, the role of men and women, fathers and mothers

A couple without children, a couple with three children and a gay couple with a son from a previous marriage, four stories intertwine.