For students of the Soviet-German war, the revelations concerning Allied signal intelligence between 1939 and 1945 only underscore our ignorance of the intelligence aspects of the second world war's greatest land campaign. Where the course and outcome of operations in western Europe, the Atlantic and the Pacific can now be seen in clearer perspective, the Eastern Front remains in twilight and shadow. The lack of Soviet documentation, always a handicap, becomes even more acute in this field, as analysis necessarily diminishes to conjecture, with the focus of research shifted away from the organization, methodology and technology of Soviet intelligence to the activities of master spies and highly-placed traitors. The results can be seen in the treatment of the Soviet espionage network known as the 'Lucy' ring, and especially in the latter's perceived decisive contribution to Soviet victory at the Battle of Kursk in summer 1943. Vital intelligence of German plans supplied by 'Lucy' has received much of the credit for defeating the longdelayed offensive (codenamed 'Zitadelle' or 'Citadel') against Soviet forces in the Kursk salient. The search for the exact identity of the intelligence sources working for Lucy has generated a prodigious amount of literature over the years, of variable quality and disparate conclusions. Far more significant than any of their findings, however, is the tendency to denigrate the performance of other Soviet intelligence services in the field. A recent study illustrates this tendency with the observation: