Abraham Cowley's reputation as a writer of love lyrics has declined steadily since the early eighteenth century. Twentieth-century commentators have tended to concentrate on biography and on details of textual accuracy. This article discusses the formal innovations and interpretive challenges of key poems from Abraham Cowley's 1647 volume The Mistress, setting their tactics of amorous persuasion in the context of contemporary debates about privacy, secrecy, and textual encoding. These debates are traced, in particular, through the publication of Charles I's encoded correspondence, seized at Naseby by Parliament's army in 1645. Through close reading, Cowley's steganographic method and 'mixt wit' are clarified for the contemporary reader as techniques indebted to Cowley's duties in managing a secretive Royal correspondence and writing at the exhaustion point of a courtly genre.