The story is set in London in 1886 and deals with Mr Adolf Verloc and his work as a spy for an unnamed country (presumably Russia). This is one of Conrads later political novels in which he moved away from his former tales of seafaring. The novel deals broadly with anarchism, espionage and terrorism. It also deals with exploitation of the vulnerable in Verlocs relationship with his brother-in-law Stevie, who has a learning difficulty.