Financial wizard "Doc" Fletcher is sent by crime boss Joe Fiore to buy a bank in Switzerland in order to more easily launder their profits. When he arrives, Fletcher finds that the bank, acquired by his associate Prince di Siracusa, consists of some shabby offices above a restaurant. To make up for this, the Prince suggests that Fletcher invests in a silver mine owned by Shireen and Agha Firdausi. This solves one problem, but the mine also attracts the attention of some of the most powerful people in the silver business. Fletcher must pull out all his wheeler-dealing skills in order to keep hold of everything he's worked for, in the process romancing a banker's discontented wife.

On the eve of World War II, zany heiress Amanda Kelly travels by train to Switzerland. While passing through Germany, she meets a sweet elderly lady, who suddenly vanishes. Distraught, she questions her fellow passengers who claim that the woman was never there. Unsure if it's all in her mind or if there's a more sinister plot afoot, Amanda teams up with photographer Robert Condon to discover the truth.