Harry (Alan Rickman) is the managing director of a design agency; Mia (Heike Makatsch) is his new secretary. Harry is comfortably married to Karen (Emma Thompson), who stays home to raise their children. He becomes increasingly aroused by Mia's overtly sexual behaviour at the office and does nothing to dissuade her. At the company Christmas party held at Mark's gallery, Harry not only enquires if Mark is Mia's boyfriend, but also dances closely with her. While at the shops, he calls her to find out what she wants for Christmas and ends up almost caught by his wife purchasing an expensive necklace from the jewellery department thanks to the salesman Rufus (Rowan Atkinson). Later on, Karen discovers the necklace in Harry's coat pocket and happily assumes it is a gift for her. When she finds a similarly shaped box under the tree to open on Christmas Eve, she is heartbroken to find it is a Joni Mitchell CD, meaning that the necklace was for someone else. She confronts Harry and asks him what he would do if he were her. She says that he has made a mockery of their marriage and of her.