At this point, Bentley thought she was spying solely for the American Communist Party. But Golos was one of the Soviet Union's most important intelligence agents in the United States. At the time when he and Bentley met, Golos was involved in planning the assassination of Leon Trotsky, which would take place in Mexico in 1940. Bentley and Golos soon became lovers. It was more than a year before she learned his true name, and, according to her later testimony, two years before she knew that he was working for Soviet intelligence.