In the twentieth century, Argentina, Chile, and Spain suffered dictatorships marked by disappearances, torture, and murder, which left wounds that, in some cases, have yet to heal. Moving these public wounds into the realm of performance, many playwrights sought to address these national traumas by creating what I call "posttraumatic theater." This book argues that these plays attempt to represent national crises by taking on stylistic features that mimic the symptoms of posttraumatic stress disorder. Drawing on trauma studies, clinical psychology, and neuroscience, Masking the Past examines the commonalities in posttraumatic theater to create a coherent theoretical foundation by which we can explore other cultural products that arise in response to traumatic events.