The article examines the intersection between Gothic elements and the theme of infection in two narrative texts by the Viennese doctor-writer Arthur Schnitzler. It argues that the re-emergence of the Gothic in modernist literature draws from the popularized scientific discourses of bacteriology around 1900 and their metaphorical imagination of germs as invisible invaders and enemies. The theme of infection functions as a Gothic trope, which is used to negotiate the experience of increasingly blurred boundaries between self and ‘other’. Schnitzler’s texts reveal how the fear of infection becomes metaphorically linked to the protagonists’ loss of their secured sense of self within the normative boundaries of a bourgeois masculinity.