Lorelei Lee is a beautiful showgirl engaged to be married to the wealthy Gus Esmond, much to the disapproval of Gus' rich father, Esmond Sr., who thinks that Lorelei is just after his money. When Lorelei goes on a cruise accompanied only by her best friend, Dorothy Shaw, Esmond Sr. hires Ernie Malone, a private detective, to follow her and report any questionable behavior that would disqualify her from the marriage.
After years of investigation, Assistant District Attorney Martin Ferguson has managed to build a solid case against an elusive gangster whose top lieutenant is about to testify.
Raoul Leduc is a police inspector trailing a spy who plots to kidnap an important American atomic scientist. Joe Victor a gangster who is hired to carry out the abduction, balks when he learns what is at stake and helps Leduc out instead.
Dr. Hohner, theatre physician at the Vienna Royal Theatre, murders his mistress, the star soprano when his jealousy drives him to the point of mad obsession. Ten years later, another young singer reminds Hohner of the late diva and his old mania kicks in. Hohner wants to prevent her from singing for anyone but him, even if it means silencing her forever.