In old Vienna, Count Seebruck (Thomas Gomez) is the impresario for the Royal Theatre. His biggest headache is his soprano diva, Jarmila (Jane Farrar). That’s why he’s more than willing to listen his aide Carl’s nephew, Franz (Turhan Bey), and Franz’s fiance, soprano Angela (Susanna Foster). Her voice sounds remarkably like the Royal Theatre long-lost star, Marcellina (June Vincent), who mysteriously disappeared ten years before.
Her disappearance is no mystery to Dr. Friedrich Hohner (Boris Karloff), the theatre’s physician. Spurned by former lover Marcellina, Dr. Hohner remembers back (in a flashback) to the night she finally rejected him, as well as her strangulation death — by his own hands. When Dr. Hohner hears Angela sing, he at first thinks it’s Marcellina, come back to haunt him again. However, when he sees Angela, he immediately schemes to silence her singing voice. Will Angela sing for the King’s (Scotty Beckett) command performance of The Magic Voice? Well….