There have been many grimoires attributed to St. Cyprian of Antioch due to his reputation as a consummate magician before his conversion to Christianity, but perhaps none so intriguing as the present unique manuscript. It is highly unlikely that the text is by the historical St Cyprian, but this does to detract from its extraordinary contents. This manuscript (unlike the more rustic Black Books of Wittenburg as found in Scandinavia, or the rather Catholic texts disseminated under his name in both Spain and Portugal) is directly in line with the Solomonic tradition, deriving input from the Heptameron, the Faustbooks of Germany, and the Goetia. It is therefore very relevant to our present series of Sourceworks of Ceremonial Magic. It is unique in that instead of being weighed down with many prayers and conjurations, it addresses the summoning and use of both the four Archangels, Michael, Raphael, Gabriel, and Uriel, a swell as their opposite numbers, the four Demon Kings, Paymon, Maimon, Egyn, and Oracus (Oriens) in a very direct way. The later are drawn in t heir animal and human forms along with their sigils, a resource unique amongst grimoires. Metatron appears as an even more powerful archangel than the usual four. The text is in a mixture of three magical scripts, Greek, Hebrew, cipher, Latin, and reversed Latin with may contractions and shortforms, but these are expanded and made plain by the editors. The title of the anuscript, Clavis Inferni sive magia alba et nigra approbata metratona, literally means "The Key of Hell with white and black magic as proven by Metatron." This wonderful, rare resource is a 96 page hard cover book