A Christian Gnostic treatise describing the unfolding of the transcendent world and the material creation. It is usually regarded as the latest extant treatise of Sethian Gnosticism. A being called Setheus plays a demiurgic role in the text, and references are made in it to two prophets, Nicotheus, whose “apocalypse” was read in Plotinus’ school in Rome in the mid-third century (VP 16), and Marsanes, whose own apocalypse is partially preserved in Nag Hammadi X. Codex Bruce Untitled is strongly influenced by third-century Platonism. Extant only in Coptic, it was originally written in Greek, probably in late third- or early fourth-century Egypt.