Marnie concludes with an ambivalent final image, which in spite of the apparently successful working through of her initial childhood trauma rejects a direct causality of neurosis. The alien body of rear-projection displays an unease that eludes the manifest closure of the narrative. Marnie sketches out such an aetiology, which in place of a definable causa for the protagonist’s illness posits an elusive cause – the proof of which is the fact that “the trauma from which the heroin suffers is in any case over-determined and cannot be unambiguously determined or resolved.” In this sense, I would like to conceive of suture theory, the re-reading of which is central to this chapter, as an aetiological project, which in contrast to the positions of Metz and Bellour does not one-dimensionally ascribe the problematic of filmic enunciation to the causality of a concrete entity (spectator/author), but, on the contrary, seeks to think through the paradox of an enunciation without enunciator. It will be shown that suture theory radically breaks with apparatus theory, by understanding the camera itself as a (non-)place of negative causality. It proposes a theory of the camera and the gaze, which conceives of the “darkness of exclusion inside the visible itself” (Althusser) as the structural cause of visibility – that is, as that very hors-champ that was dismissed as being a placeholder for the enunciator.