The Mandaean proselyte Meryay, best known from her representations in the Canonical Prayerbook, the Great Treasure (Genzā Rabbā), and the Book of John (Drāši d-Yaḥyā), serves as an illuminating example of the sort of figure who partially and ambiguously bridges the interests and concerns of differently constituted religious communities, allowing for a certain degree of collaboration between them. Christians readily identify this Mandaean figure with Mary, the mother of Jesus, and Muslims similarly identify her with Maryam bint ʿImrān of the Qur’ān. Mandaeans today identify their Meryay with neither of the above, insisting that theirs was a different woman of the same name, but prior generations were content to permit such identifications in the interest of dialogue across religious boundaries. In its most extensive retelling, that of the Book of John, her legend situates her at a literal boundary, the Euphrates, where a pursuing Jewish host is drowned, in an inversion of the Exodus narrative. These days, however, she stands not at the boundary but rather the center of the debate over contentious issues such as the permissibility of conversion and the role of women in the priesthood.