In his Babyloniaka (second century CE), Iamblichus devotes an important part of the narration (as it is summarized by Photius) to events occurring in a very particular place: an unnamed island formed by the Tigris and the Euphrates. This paper aims to show how Iamblichus has intermingled times, places, identities and genres to create a permeable world which reflects the pluricultural identity of the author. The island concentrates levels of reality which are usually separated to construct a geographically and ontologically hybrid world, which is enigmatic and paradigmatic of the novel as a whole. In accordance with a permeable genre, Iamblichus has constructed a permeable world, which seems to be characteristic of an author who has several geographical and cultural roots.