As a result of the negotiation of the agreement in Bazán Ferrol, thousands of workers marched in a demonstration on March 10, 1972. In the midst of the dictatorship, the Armed Police fired on the demonstration, with dozens of wounded and two workers killed: Daniel Niebla and Amador Rey. The film addresses the entire process of penetration of the worker commissions and the communist party into the shipyard, the tensions in the negotiation of the agreement, the events of March 9 and 10 and their international repercussions. as well as the so-called 'Process of the 23' in which the main labor leaders were tried three years later.

• Documentary