This chapter explores the literature of possession through its persistent evocation of the ‘impressionable mind’, a trope that submits photographic technology as a privileged figure for the subject’s permeability. It centres on Sydney Atherton, the peculiar hero of Richard Marsh’s The Beetle (1897), who is a narrator less inclined to write than to be written upon. Before resorting to descriptive narrative techniques, he appeals to his own body as an archive of the event. Atherton’s ‘retinal print’ is conversant with the Victorian urban legend of the optogram—the scientifically spurious hypothesis that traumatic events physically imprint themselves upon the eye in a manner resembling the photographic process. The Beetle’s association of hypnosis with photography impels us to consider the contemporaneous development of ‘the negative’ within photographic and psychoanalytic discourse. Integrating Victorian optics and the psychophysiology of perception, Marsh’s novel intimates that the gaze radiates not from within the subject, but towards it from the objects it views. The ‘negative’ bears witness to the impact of that inverse gaze, embodying the dimly understood influence of another that founds the shadowy substrate of our being.