 In the spring of 1939, Paul, the Schumachers and Küchenmeister travelled to Switzerland, ostensibly to treat Küchenmeister's tuberculosis but also with a secondary agenda that was to contact the KPD director Wolfgang Langhoff, in order to be able to exchange information.In August, he helped Rudolf Bergtel to reach Switzerland, and provided him with information on current German aircraft and tank production, as well as deployment plans for a German submarine base in the Canary Islands.On his 30th birthday on 2 September 1939, Schulze-Boysen had an intensive conversation with the German industrialist Hugo Buschmann, with whom he had agreed to receive literature on the Russian Revolution as well Lenin, Stalin, and Leon Trotsky.