Complex sentence: Following his recruitment, Fisher worked for the OGPU as a radio operator in Norway, Turkey, United Kingdom, and France then returned to Russia in 1936, as head of a school that trained radio operators destined for duty in illegal residences.
Split into simpler sentences: Following his recruitment, Fisher worked for the OGPU as a radio operator in Norway, Turkey, United Kingdom, and France. He returned to Russia in 1936, as head of a school that trained radio operators destined for duty in illegal residences.