The notion of error plays an important role, this article argues, in Per Olov Enquist’s groundbreaking documentary novel Legionärerna (The Legionnaires) (1968), which depicts the controversial Swedish extradition of Baltic soldiers in January 1946. In terms of the plot (re)constructed by Enquist, Swedish politicians and Baltic soldiers as well as the novel’s investigator, a kind of alter ego of the author, constantly make errors in their decisions and actions. And by letting characters, investigator and narrator refer to the course of events as a tragedy, Enquist connects the phenomenon of error that permeates his novel with the concept of hamartia in the classical drama. In correspondence with the ancient Greek view that the error of the tragic hero is caused by a lack of knowledge, Enquist’s novel understands the errors of its characters and its investigator as resulting from ignorance and incorrect reasoning, and thus, the article concludes, embraces a premodern intellectualistic anthropology.