When Lord Charles Spencer, Baron Woford, tells his sister Cleo Jones that he won't join the family for Christmas at Daventry Hall, Cleo summons her sisters-in-law, and the three sisters determine to find out what's making Charles sad. Is it politics or love? They enlist the aid of Robin Jones of the new detective force in London, and when Robin discovers that for Charles, love and politics don't mix because he's fallen in love with the granddaughter of a man from the opposition, the sisters hatch a plan to overcome political division and bring Charles together with the woman he loves on Christmas Eve.