Although the relationships between Eugene O'Neill's plays and those by Susan Glaspell started being studied even by the critics of the day, this comparative analysis requires further attention, above all to reassess O'Neill's early one-act plays—usually dismissed by scholars as the products of O'Neill's amateur spirit. This article invites readers to locate Glaspell's and O'Neill's plays within the theoretical framework of dramatic geopathology, which, as put forward by Una Chaudhuri, privileges the special relation between character and space as the motor that drives plot. By applying this concept, this article examines the rich net of intertextual references that go from Glaspell's Trifles to O'Neill's Before Breakfast and from Glaspell's The Outside to O'Neill's Exorcism. Overall, this article aims to show not simply that Glaspell was a determinant influence on O'Neill's dramaturgy but, more important, that the readings and interpretations of O'Neill's early plays are surprisingly different if mapped against a response to Glaspell's plays. Furthermore, this article argues that thanks to Glaspell's influence, O'Neill was able to articulate and exorcise his inner demons through these early autobiographical dramas.