 Complete the following phrase:  Richard Sorge was recalled to Moscow in December 1932 and drew the attention of his intelligence chiefs to his talented young recruit, Ursula Hamburger. In May 1933 Ursula was invited to Moscow for a training period lasting at least half a year. She was given the cover name Sonja, and received appropriate political and technical schooling. After almost a year, in April 1934 she returned to Shanghai accompanied by her new handler, Johann Patra cover name Ernst, and the two of them then continued on to Mukden today known as Shenyang where they had been sent by Moscow. Maik, now aged three, was returned from Europe and went to live with his mother in Mukden. Rudolf Hamburger remained in Shanghai. The impact of fascist government policies in Germany and Japanese aggression drove him ever more uncompromisingly towards Communism. In May 1934 he began to undertake small services for his wife and Johann Patra in connection with their work for the GRU. However, it is clear that at this point his contribution was provided in terms of support for his wife rather than as an intelligence agent on his own account. Ursula Hamburger was providing a communications link to Moscow for Chinese partisan groups engaged in fighting the 