Letter Beyond the Walls reconstructs the trajectory of HIV and AIDS with a focus on Brazil, through interviews with doctors, activists, patients and other actors, in addition to extensive archival material. From the initial panic to awareness campaigns, passing through the stigma imposed on people living with HIV, the documentary shows how society faced this epidemic in its deadliest phase over more than two decades. With this historical approach as its base, the film looks at the way HIV is viewed in today's society, revealing a picture of persistent misinformation and prejudice, which especially affects Brazil’s most historically vulnerable populations.