In the last few years, incel violence has been the subject of many excellent journalistic accounts, but — with few notable exceptions, whose insights will be acknowledged and valued throughout this research paper — there has not been much scholarly output addressing the phenomenon. Individuals who self-identify as involuntary celibates are being radicalised into believing that the world is dominated by women and attractive men, and their marginalisation depends on this domination within what incels often term the mating market. After a number of violent attacks in which the perpetrators were linked in various ways to the inceldom — the status of involuntary celibacy — researchers have started to debate whether incel violence should be considered terrorism or not. This paper examines the pillars of incel ideology through an analysis of incels’ own vocabulary and narratives. Based on this analysis, it introduces two distinct research hypotheses. First, it argues that, while consensus is being gradually reached on considering incel violence as terrorism, scholars do not possess an effective analytical framework for studying the broader incel communities and, in order to partly fill this gap, a proper notion is that of a radical milieu, i.e. a community where radicalisation occurs. The second research hypothesis suggests that the radicalisation power of this milieu lies in the external locus of control that most incels adopt and take to the extreme in their perception of themselves and of inter-sex relations.