A fateful day reunites an estranged family in Mexico City, where a chain of events shifts their romantic relationships and uncovers a monumental secret.

Elena is a single mother dependant on Social Services. Her son Tom has behaviour issues and is stigmatised at school as a "problem child". An absent father further complicates their difficult relationship. Tom is diagnosed with Attention Deficit Hyperactivity Disorder and given psychiatric medication, but a strange accident alerts his mother as to their side effects. When she refuses to continue administering the drugs to him, Social Services threaten to take Tom from her.

Azucena, a woman in her thirties, approaches Julio, a teenage boy living in a group home, for reasons he doesn’t understand. As they spend time together, an uneasy closeness grows, changing the shape of a bond neither expected to find.