A transcultural adaptation of a literary work often reveals aspects of the original that had previously been obscured in its native context. In a similar vein, a creative reading that truly attempts to do justice to its object might be said to betray it, both in the traditional sense of being unfaithful to mainstream interpretations of the text and in the more revelatory sense of the word whereby a reading betrays, or divulges, a previously unacknowledged aspect of the work. This essay considers a particularly provocative “betrayal” of G.K. Chesterton's The Man Who Was Thursday by the Russian director Alexander Tairov. This fantastic novel by Chesterton is itself the site of multiple betrayals, both in the plot-level reversals of its characters and in its use of the oscillating narrative style characteristic of the fantastic literary mode. The resulting undecidability of the work makes it difficult to interpret confidently, although this doesn't stop some readers from assuming such epistemological confidence. I suggest that “faithful” readers of the text, including the retrospective author himself, err when they attribute a fixed meaning to the novel, viewing it as a straightforward, culturally reactionary “anti-anarchist romance,” and thereby precluding other, more politicized, readings. By staging a creative betrayal of the novel in 1920s Moscow, Tairov and Sigizmund Krzhizhanovsky, who was commissioned to write the script, reactivate certain elements of the work obscured by attempts to firmly establish its interpretation. In the context of the revaluation of fidelity accomplished in recent ethical discourse, I ultimately argue that an appreciation for the revelatory potential of such literary betrayals can foster an openness to the unknown that is vital for meaningful, decisive cooperation in an ethico-political sphere that is incurably undecidable.