Set in the 90s, Brotherhood follows the story of Cristina, an honest and dedicated lawyer that finds that her brother has been jailed for years and is a leader of an ascendant criminal faction. Coerced by the police, she is forced to become an informant and work against the brother she idolized as a child. But as Cristina infiltrates the Brotherhood, she begins to question her own values about law and justice and comes into contact with a dark side of herself she did not imagine she had.