His destination, this time, was Turkey, from where he was to provide intelligence reports on developments in the Middle East. In order to address the potential limitations of travelling on his Honduras passport, he intended to travel by train to Vladivostok and from there, by sea, to Shanghai. From there he would be able to travel legally through India and Iran to Turkey without having to apply for a visa. This journey did not work out quite as planned, however, since on 22 June 1941, in breach of the non-aggression deal between Nazi Germany and the Soviet Union, German troops stormed across the frontier. After rapidly knocking out the Soviet Union, the German plan was to continue through to Iran and capture the oil fields. The Great Patriotic War became suddenly urgent and there were no more ships sailing from Vladivostok to Shanghai. Hamburger was summoned back to Moscow. His handlers did not cancel his assignment, however. Since the original itinerary was impossible because of the absence of a sea passage from the est of the country to Shanghai, and alternative plan was devised whereby the various visa stamps would be added in his Honduras passport by Soviet intelligence, providing a forged trail indicating that he had traveled via Shanghai and India to Tehran. Then, during the Autumn of 1941, he drove across by the land route via Tbilisi in Georgia and through Armenia to Tabriz near the border in northern Iran. That meant that regardless of his passport stamps, he had to this point made the entire overland journey through territory controlled by the Soviet Union. By October 1941 he had reached Tehran.