This article explores the myriad ways that Polish and Ukrainian residents engaged in violent and cruel behavior during World War II through a case study of the Chełm region. Under Nazi occupation, this formerly peaceful community exploded into a horrific scene of nationalist and popular violence. Jews were widely assaulted by their Polish and Ukrainian countrymen; Poles and Ukrainians engaged in mutual killings and ethnic cleansing; rural villagers were subjected to countless raids from area partisans; and escaped Soviet POWs were often denounced or otherwise attacked by area residents. Treating this outbreak as a whole, I argue that anti-Jewish violence was embedded in a vicious social transformation that engendered an array of crimes against multiple groups. By interweaving the fates of different ethnicities into a single study, my paper contextualizes Polish complicity during the Holocaust and highlights the sordid interactions between the German invaders, Jewish citizens, and local Christian society.