After a chance train encounter with Laurence Knight, Tom Blake's family's fortunes prosper on the beneficence of the great financier. A developing friendship leads to the Knights selling their home to the Blakes when they move back to London. All looks rosy for the Blakes as share prices in Mr Knight's new business venture soar, but is their confidence misplaced?

During the Second World War a British schoolteacher working in Denmark is caught up when the Germans invade.