The Comintern agent Arnold Deutsch was an Austrian Jew who had travelled to London from Vienna in May 1934. His instructions from Moscow Centre were ‘to cultivate young radical high-fliers from leading British universities before they entered the corridors of power’. In 1936, with his wife Josefine, a trained NKVD wireless operator, he moved into No. 7 Lawn Road Flats, a furnished studio flat on the ground floor at the monthly rate of £4 4s, to be paid weekly. Deutschs flat was only two doors from the Soviet agent Brigitte Kuczynski, a German Jew, who lived in Flat 4 with her Scottish husband A. G. Lewis, a member of the CPGB. Gertrude Sirnis, who knew the Pritchards through her work with the Quakers, had made the arrangements for Brigitte to move into Lawn Road Flats in 1934.

Brigitte Kuczynski, or Bridget Lewis as she now was, and Arnold Deutsch worked for different Soviet intelligence agencies – the GRU and OMS respectively – and came from very different Marxist traditions. The German Communist Party, the KPD, was very much in the Stalinist mould and in thrall to the Soviet-dominated Third International; whereas the Austrian Communist Party, the OKP, was still strongly influenced by the ‘revisionist’ ideologies of the pre-war Second International and the Austro-Marxism of Otto Braun.