Sentence:  Three years after Stalin's death, with ghostly figures returning to Moscow and Leningrad from Stalin's <WSD>death camps</WSD>, the leaders in the Kremlin agreed that Stalin's ghost had to be laid to rest if they were to get on with the reforms that would allow them to stay in power. 
Meaning of the word marked with <WSD> tags:  A prison camp in which a large number of prisoners die for various reasons, such as starvation, disease, brutality and neglect.