I have been reading Special Tasks the memoirs of Pavel Sudoplatov who headed the NKVD's Special Tasks 4th Directorate - roughly the equivalent of SOE. Earlier he had been involved in Trotsky's assassination. According to Sudoplatov the Russians deployed 212 Guerrilla Detachments totaling 7,316 men. in addition they trained 1000 saboteurs for the Red Army, 3,500 civilian saboteurs, and 3000 further agents were parachuted behind Axis lines. They claim to have killed 137,000 Germans with 87 high ranking officers and officials assassinated, 2,045 Axis agents and police were liquidated. He details help given by Philby and Cairncross, as well as the penetration of Los Alamos and the birth of the Russian nuclear programme. His comments on the supply German weapons to Palestinian Zionists is interesting as is Stalin's plan for a Jewish homeland in the Crimea. Post war he was purged and spent time in the Gulag.
This sounds interesting (for me) - anything to do with Russian history, especially the 20thC. I see it's available on Amazon so should be my next read.