In 1903, American seaman Henry Adams (Gregory Peck) is stranded penniless in United Kingdom of Great Britain and Ireland and gets caught up in an unusual wager between two wealthy, eccentric brothers, Oliver (Ronald Squire) and Roderick Montpelier (Wilfrid Hyde-White). They persuade the Bank of England to issue a one million pound banknote, which they present to Adams in an envelope, only telling him that it contains some money. The reason for this is that Oliver believes that the mere existence of the note will enable the possessor to obtain whatever he needs, while Roderick insists that it would actually have to be spent for it to be of any use.