The first-person narrator, the write of the journal that makes up this epistolary novel, takes on three identities. All are a bespectacled, slender, young man in his mid-thirties. While in the labyrinth, the narrator does experience some slight physical changes from strenuous fishing, walking, and other activities, but most of the differences between the personas are psychological.

The Beloved Child of the House is what the narrator calls himself, identifying as a “scientist and an explorer” (6) who is extremely knowledgeable about the House. Slowly he realizes he is an unreliable narrator because he “had forgotten many things!” (108). He is a solitary and pragmatic identity created after the narrator lost the memories associated with being Matthew Rose Sorensen.

Piranesi is what Ketterley calls the narrator, but even in his most disassociated state, he does not “think that it is [his] name” (134). Ketterley references the Italian artist of the Carceri d’invenzione, saying, “I have to call you something. And it suits you. It’s a name associated with labyrinths” (163). Piranesi is also “a romantic” (143), according to Ketterley. Most importantly, the name Piranesi hides Ketterley’s abduction of the narrator; it aids in keeping the Sorensen identity mentally imprisoned.

The writer and journalist Matthew Rose Sorensen is never fully recovered; the labyrinth essentially killed this identity.