On the eve of World War II, Dr. Franz Adler, an Austrian Jew and renowned surgeon, is swept up in the wave of anti-Semitic violence washing over Vienna and flees to Shanghai with his daughter. There, at a Shanghai refugee hospital, Franz meets and falls in love with an enigmatic nurse, Soon Yi "Sunny" Mah. When the Japanese ally themselves militarily with Germany and overrun Shanghai, Adler struggles to keep the refugee hospital open while protecting his own family and trying to save the city's Jewish community from a terrible fate.