The 'key principle' as a complementary procedure to cryptographic writing and deciphering reading is demonstrated here with reference to various narrative texts, beginning with the courtly romance, extending to Chr.M. Wieland's »Geschichte der Abderiten«, Goethe's »Die Leiden des jungen Werther«, and E.T.A. Hoffmann's »Meister Floh«, and proceeding from there to discuss early 20th century novels with artists as their central figures, and the works of Thomas and Klaus Mann (»Mephisto«, »Doktor Faustus«). The roman à clef emerges cleansed of its opprobrium as a 'suspect' form of literary activity, and stands revealed as an instance of covert reference that invariably casts a highly illuminating light on the societies occasioning its use.