[2] The son of a Jewish blacksmith, when Mukasei he was 18 he started studying at the Institute of Oriental Languages in Leningrad, specializing in Bengali and English.
In 1937 he was ordered by the Communist Party of the Soviet Union to study at the Intelligence School of the Workers' and Peasants' Red Army.
[3] From the 1940s through the 1970s, Mukasei, along with his wife Elizaveta (codenamed Elza), took part in a number of undercover operations in Western Europe and the United States.
He wrote training manuals for reconnaissance work and was a professor at the Russian Academy of Security, Defense and Law Enforcement.
In December, 2004, Mukasei published a book of their memoirs called Zephyr and Elsa in which they wrote about their thirty years of work and life abroad.