Mark Lewis, a shy and reclusive photographer, works by day as a focus-puller at a film studio and, by night, captures provocative images of women for a seedy newsagent's pin-up business. Mark's true obsession, however, lies in his side project: he films the faces of women at the moment he murders them, using a hidden knife on his camera tripod to capture their final expressions of terror. His disturbing fascination with fear is rooted in a traumatic childhood, subjected to cruel experiments by his father, a renowned scientist studying fear response. Mark meticulously documents his murders, creating a twisted archive of terror.

Things begin to change when Mark befriends Helen Stephens, a kind-hearted tenant in his building, and her curious nature slowly draws her closer to his dark secret world. As he starts spending more time with Helen and her kindly blind mother, his carefully maintained facade begins to crack, and he struggles to keep his deranged compulsions hidden. Helen’s growing attachment to Mark puts her in grave danger as she inches closer to uncovering his horrifying truth. Mark's dual existence as both a killer and a disturbed yet sympathetic figure spirals toward an inevitable confrontation between his inner demons and the possibility of redemption.