In a confessional, first person narrative, the concept of truth and how it is constructed and perceived is important. Truth in fiction can be created and interpreted in a number of different ways, and when the narrative that portrays it in addition is unreliable and ambiguous, discerning truth becomes a decidedly complex process. This essay interprets the confessional testimony of the narrator in John Banville’s The Book of Evidence, in order to examine the function of these narrative devices and how they affect the understanding of what is true in Banville’s unreliably narrated novel. It does so by following literary theories regarding unreliable narration by Tamar Yacobi and others, as well as theories of truth in fiction as first presented by David Lewis and expanded upon by Ben Levinstein and others. The different types of ambiguity suggested by William Empson are also considered. The novel’s narrative is analyzed specifically in relation to the understanding of how the protagonist eludes to his feelings of guilt and shame. These emotions are chosen for their prevalence in conventional confessions. The essay claims that the narcissistic narrator harbors neither of these feelings pertaining to the crime he has committed, but rather that he admits to being guilty and is ashamed of being caught, and that this is portrayed through the structure of the narrative rather than its content.