This article will examine the course of the factional struggle between Yugoslav communists that developed behind the frontlines of Spain in 1938 and investigate the involvement of foreign communists in their dispute. I will attempt to contextualize the struggles inside the Communist Party of Yugoslavia (KPJ) within broader power dynamics of the Comintern during the Great Purge, in order to gain a better understanding of both the KPJ and the Comintern as a whole in this period. The main organizer of the Yugoslav volunteers for the cause of the Spanish Republic, the KPJ, found itself in one of the most turbulent periods of its history at this particular time. In August 1937, its general secretary was arrested in Moscow and charged with espionage. The news of the arrest soon reached the volunteers in Spain, and many of them became engulfed in the emergent factional conflict, while struggling to make sense of the situation based on fragmentary information from abroad.