Tucumán 1975, a milestone in Argentine history and what would be one of the most tragic events intersect: the SMO (Compulsory military service) and the "Operative Independence". Through the story of those young people who made the "Colimba" we learn about their experiences, from the day of the raffle to the details of life in the barracks and the transfer to Mount. "SMO, the forgotten battalion" tries to rescue from the oblivion imposed by official history, those young loons who lived those bloody years of our history from a trench in which destiny placed them, in a random way, through a lottery.