In today’s world, the Internet has become an integral facet that conditions our lives both epistemologically and ontologically. Thus, a theater work that engages with the problem of Internet also should situate it as the center of its dramaturgy, not merely as a topic in the story or as spectacular décor. Firefall, by New York-based playwright and director John Jesurun, which premiered in 2009, can be regarded as such a work. On one hand, the piece engages with the technology of computers and the Internet and, on the other, has a dramatic text. This duality is, as theater critic Bonnie Marranca said, the distinctive feature of the piece. This paper aims to clarify the details of this duality and its effect and, thus, evaluate Firefall as a response from theater arts to a post-Internet world. This paper focuses on two issues from Firefall. The first can be referred to as an access to reality. In Firefall, Jesurun constructed a purpose-built website and performers and staff used their respective laptops to access the site during the performance. Considering the actual existence of the Internet to which the Firefall website belongs, we can find here an access to the reality that destabilizes the closed completion of a piece of work as fiction. More important is the second issue, the unrelatedness of the double task and the consequent suspense. As stated above, performers were required to operate laptops while simultaneously acting the roles of fictional characters. As a result, this double task is literally irrelevant; for example, they do not paradoxically illuminate the other task as seemingly irrelevant counterpoints. In the course of the performance, a performer who is designated as an “interrupter” occasionally disrupts the others’ acting by abruptly playing movies on the website. However, given the above-mentioned irrelevancy, what this interruption brings should not be understood as a sort of Brechtian A-effect. It is a suspended moment that is separated from both operating gestures and representational acting and can be considered to be an accident in the performance. In the conclusion section, referring to a discussion about failure by performance studies scholar Sara Jane Bailes, I propose an understanding that interprets Firefall’s accident as a generative moment. It is the moment when the exteriority of technology to our lives becomes obvious and thereby, in fact, brings a better understanding of it. Then, the border of success and failure would become more obscure.