Anglo-Saxon literature, densely populated with runic, acrostic, riddling, and other grammatological manifestations, evinces a profoundly cryptographic imagination. Such an imagination, as Shawn Rosenheim describes it, is demonstrated through "a constellation of literary techniques concerning secrecy in writing". The substitution of runes for Roman letters, or for words, was in their eyes only the most literal manifestation of a truth about all signs; the capacity of writing to store and silently convey words, thoughts, intimacies, and oaths across both time and distance held a potent grip on the Anglo-Saxon imagination. Attempting to explain how knowledge of the inscrutable could be had in this world, St. Augustine wrestled persistently with the nature of signs and things. In Anglo-Saxon literature surveyed in this chapter, cryptography models a form of communication through which the secret knowledge of God might pass, obscure but accessible, from the realms usually forbidden to men.