The TV series "Russian Roller Coaster" is a domestic spy drama set in post-war USSR. Frontline friends Petr and Mark meet governess Tanya in the Russian south. She is raising the daughters of British agent Harper, whom she secretly loves. When the Englishman is exposed by intelligence agencies, Tanya also ends up in prison, where she gives birth to his third daughter. But the heroes do not yet know how their destinies will intertwine. Years later, Mark and Petr will marry Harper's older daughters and live as one big multinational family.