The impoverished Earl and Countess of Dunmow are preparing a dinner at their flat in Chelsea for the wealthy Grand Duchess of Monteblanco (where the Earl was once ambassador) and her son Prince Phillipe. They are hoping that they can encourage the Prince into marrying their recalcitrant daughter Susan. Despite food burning in the oven, demands from an errand boy for payment of overdue grocer's bills and the eccentricities of Mrs. Kneebone, hired as domestic help for the occasion, the plan is eventually successful.[4]