Alice Domon & Léonie Duquet are French nuns who were kidnapped, tortured and dumped into the sea during one of the infamous "vuelos de la muerte" or "death flights", a habitual practice under the military dictatorship in Argentina. This was the first incident to bring the International Community's attention to what was going on in Argentina. The film tells the story of the nuns' lives, from their arrival in Argentina to help the poor, to their betrayal with a kiss on the cheek from a man they believed to be a friend, but who was in fact an undercover infiltrator, Captain Alfredo Astíz.

Algo habrán hecho (They must have done something) is testimony to the self-sacrifice, passion and heroism of anonymous people who believe in a fairer society, willing to make the ultimate sacrifice in their attempt to achieve it.