In the near future, the Government aims to replace judges with Artificial Intelligence software, pledging to effectively automate and depoliticise the justice system. Carmen Costa, a distinguished judge, has been invited to assess this new procedure. However, when the software's creator is found dead, she realizes her life is in danger and that she will have to fight the powerful interests that are at play in the highest echelons of the State. Galician Simón Casal takes the debate the boundaries of Artificial Intelligence one step further in a gripping thriller of political conspiracies.

Two sisters turns in the center of a plot implying wolfram, Nazis, Franco's prisoners and British spies.