Abstract Stuart Hall, a founding scholar in the Birmingham School of cultural studies and eminent theorist of ethnicity, identity and difference in the African diaspora, as well as a leading analyst of the cultural politics of the Thatcher and post-Thatcher years, delivered the W. E. B. Du Bois Lectures at Harvard University in 1994. In the lectures, published after a nearly quarter-century delay as The Fateful Triangle: Race, Ethnicity, Nation (2017), Hall advances the argument that race, at least in North Atlantic contexts, operates as a ‘sliding signifier,’ such that, even after the notion of a biological essence to race has been widely discredited, race-thinking nonetheless renews itself by essentializing other characteristics such as cultural difference. Substituting Michel Foucault’s famous power-knowledge dyad with power-knowledge-difference, Hall argues that thinking through the fateful triangle of race, ethnicity and nation shows us how discursive systems attempt to deal with human difference. In ‘Fateful Triangles in Brazil,’ Part II of Contexto Internacional’s forum on The Fateful Triangle, three scholars work with and against Hall’s arguments from the standpoint of racial politics in Brazil. Sharon Stanley argues that Hall’s account of hybrid identity may encounter difficulties in the Brazilian context, where discourses of racial mixture have, in the name of racial democracy, supported anti-black racism. João Nackle Urt investigates the vexed histories of ‘race,’ ‘ethnicity’ and ‘nation’ in reference to indigenous peoples, particularly Brazilian Indians. Finally, Thiago Braz shows, from a perspective that draws on Afro-Brazilian thinkers, that emphasizing the contingency of becoming in the concept of diaspora may ignore the myriad ways by which Afro-diasporic Brazilians are marked as being black, and thus subject to violence and inequality. Part I of the forum – with contributions by Donna Jones, Kevin Bruyneel and William Garcia – critically examines the promise and potential problems of Hall’s work from the context of North America and western Europe in the wake of #BlackLivesMatter and Brexit.