Harry is the managing director of a design agency; Mia is his new secretary. For Christmas he buys her an expensive necklace from jewellery salesman Rufus , who elaborately wraps while Harry becomes increasingly nervous with the fear of detection. Meanwhile, Harry's wife Karen is busy dealing with their children, Daisy and Bernard , who are appearing in the school Nativity play. Karen discovers the necklace in Harry's coat pocket and initially assumes it is a gift for her; she later confronts Harry over the necklace and he admits his foolishness.