Vauck lead the team at Referat 12 that would eventually discover the German anti-fascist network that would later be called the
Red Orchestra () by the Abwehr. Dr Vauck succeeded in decrypting around 200 messages of the Rote Kapelle. The first discovery of the network was the discovery of the woman agent,
Rita Arnould on 12–13 December 1941, which later led to the locating of radio operator
Johann Wenzel, the second discovery. On 15 July 1942, the discovery that lead to the full realisation of the size and complexity of Rote Kappelle was made, when a message was deciphered. On that date, Vauck successfully deciphered a message. It had the format: ::
KL 3 DE RTX 1010-1725 WDS GBT FROM DIREKTOR TO KENT PERSONAL: that was decoded into;
KENT from Director Personal. Proceed immediately Berlin three addresses indicated and determine causes failure radio connections. If interruptions recur take over broadcasts. Work three Berlin groups and transmission information top priority. Addresses: Nwuwestend, Altenburger allee 19, third right; Coro Charlottenburg, Frederikstrasse 26a second left, Wolf-Friedenau, Kaiserstrasse 18 fourth left. Bauer. Call name here "Eulenspiegel" Remind Bauer of book gave to Erdberg as present before the war and of play Till Eulenspiegel. Password Director. Report progress 20 October. New (repeat new) plan in force for three stations. When Vauck decrypted this message, it was forwarded to
Reich Security Main Office IV 2A, where they easily identified the persons living at the three addresses and from 16 July 1942 were put under surveillance. Unknown to Vauck, there was also a informer working in Referat 12 in Vauck's team, Corporal
Horst Heilmann, who was supplying
Harro Schulze-Boysen (Coro) with intelligence. Heilmann tried to contact Schulze-Boysen but was unsuccessful and left a message with his wife to phone him back. Schulze-Boysen eventually did this, but Heilmann was absent. However Vauck answered the phone and when he requested the name of the caller to take a message, and was met with
Schulze-Boysen, who was already identified as CORO, the deception was revealed, and Heilmann was arrested. ==References==