Gorsky joined the Soviet secret police in 1928 and worked in the internal political police. In 1936 he transferred to foreign intelligence and was sent to England as cipher clerk and assistant to the London "rezident". During the Great Purge of 1939 the London "rezidentura" was liquidated, and in March 1940 Gorsky was recalled to Moscow. Gorsky survived the purges and was appointed London "rezident" in November 1940, during the Hitler–Stalin Pact. In London his first cover was attaché, then second secretary of the Soviet embassy.