Soviet intelligence spouses — Lyudmila ("Lyre") and Fyodor ("Starling") Grekov at the beginning of the Great Patriotic War are tasked with settling in Germany. Personnel intelligence officers with vast experience are successfully introduced into German society and begin to work actively. At the end of the war, during the bombing of Berlin, fate separates them, but then they will meet in the new Germany and continue their work.

About how Soviet border guards managed to detect and neutralize foreign intelligence agents.