We live in their buildings, work in their companies, shop in their stores, eat in their restaurants and elect politicians they fund. Founded more than 150 years ago by shepherding families in the toe of Italy, the 'Ndrangheta is today the world's most powerful mafia, with a crushing presence in Southern Italy, a market-moving size in global finance and a reach that extends to 50 countries around the world. And yet, remarkably, few of us have ever heard of it.

The 'Ndrangheta's power rests on a code of silence, omerta, enforced by a claustrophobic family hierarchy and murderous misogyny. Men and boys rule. Girls are married off as teenagers in arranged clan alliances. Beatings are routine. A woman who is 'unfaithful' - even to a dead husband - can expect her sons, brothers or father to kill her to erase the 'family shame'.

In 2009, when abused wife Lea Garofalo 'disappears' after giving evidence against her mafiosi husband, prosecutor Alessandra Cerreti realises the 'Ndrangheta's bigotry may be its great flaw. The key to bringing down this criminal empire is to free its women and allow them to speak out and testify. When Alessandra finds two collaborators inside Italy's biggest crime families, she must persuade them to cooperate and save themselves and their children. The stakes could not be higher. Alessandra is fighting to save a nation. The mafiosi are fighting for their existence. The women are fighting for their lives. Not all will survive.