The paper introduces the Greek original of the hagiographic text The Narration of Our Father Agapius (presumably from the 5th–6th centuries), which was widely known in Slavonic tradition but remains almost unknown neither to historians of Byzantine culture and to Slavists. The paper consists of two parts. Drawing upon the critical edition of the text, the first part discusses the peculiarities of the Greek tradition. The manuscript from Athens is much more accurate than the second of the two existing Greek manuscripts, from St. Petersburg. Nevertheless, in some cases the Athenian manuscript is defective. Thus, the first culmination of the narrative, the description of the theophany in the Garden of Paradise, is absent. The episode of the raising of the dead son of a widow is also reduced, probably due to its somewhat magical flavor. However, the manuscript from St. Petersburg in its second part is inferior to the Athenian manuscript reducing vast descriptions—prayers and various details of the rites. A comparison of the two Greek manuscripts reveals vivid folkloric and evangelic images of the Greek original that were concealed by various mistakes made by scribes. The second part of the article compares the Greek original of the Narration with the Slavonic translation. The text from the Uspenskij Sbornik is the main focus of the comparison, but other evidence from the South and East Slavonic traditions are also taken into account. The translation eliminated quite a few major traces of the Greek original. Thus, an intimate first-person narration and a striking detail in which the main character himself tells about his death are eliminated. The names of Paradise sites, theological discourses, exhortations, any vast descriptions disappear. The adjusted symbolic structure of the Narration that reveals the transformation of the character from myst to mystagogue is eliminated in the Slavonic tradition and the main idea of the Greek text—the idiorythmia predominating over the koinobion—is scarcely readable. In the Slavonic tradition the text becomes more and more similar to a fairytale.