Lovely young Frenchwoman Ranie Racine (Annabella) leads a privileged existence in Paris with her adored banker father (Stewart Rome). But when her dad is murdered and the police declare it a suicide, Ranie auctions the family heirlooms, gets a job selling jewelry and travels incognito to Monaco to hunt down the killer. When she encounters charming government man Paul de Brack (David Niven), it's love at first sight -- until she suspects him of having a hand in her father's murder.