We examine the Ascension of Isaiah, an important Jewish-Christian apocalypse of the second century with a long history in later esoteric Christianities. The text gives us important insights into the struggles within the early church for authority between visionary, prophetic inspiration and hierarchical canonicity, and the ways in which the early church dealt with the inconvenient fact that the Rapture hadn't happened according to schedule. It also presents a deluxe terrain of angelic palaces and thrones, themes of descent and ascent, and some juicy details relating to ascent as a spiritual practice in antiquity.