A witty, romantic, and very dangerous love story about chance meetings, instant attractions, and casual betrayals. Two couples disintegrate when they begin destructive adulterous affairs with each other.
In the opening scene, 24-year-old “Alice Ayres” (Portman) and Dan Woolf (Law) see each other for the first time from opposite sides of a street as they are walking toward each other among many other rush-hour pedestrians. “Alice” is a young American stripper who just arrived in London, and Dan is an unsuccessful British writer who is on his way to work, where he writes obituaries for a newspaper. She looks in the wrong direction as she crosses the street and is hit by a taxi cab right in front of Dan’s eyes. After he rushes to her side, she smiles to him and says, “Hello, stranger.” He takes her to the hospital, where Alice is treated and released. Afterward, on the way to his office, they stop by Postman’s Park, the same park that his father and he visited after his mother’s death. Pausing in front of the office before he leaves her and goes to work, Dan reminds her that traffic in England tends to come on from the right, and on impulse, he asks her for her name. They soon become lovers.
A year later, though the two are in a relationship, Dan is straying. He has written a novel based on Alice’s life, and while being photographed to publicize it, he flirts with the American photographer Anna Cameron (Roberts). Anna shares a kiss with Dan before finding out that Dan and Alice are in a relationship. Alice arrives and uses Anna’s bathroom, leaving Anna and Dan alone again. Dan takes the chance to try to persuade Anna to have an affair with him, but is cut short by Alice’s return. Alice asks Anna if she can have her portrait taken, as well. Anna agrees and Alice asks Dan to leave them alone during the photo shoot. While being photographed, she reveals to Anna that she overheard them, and she is photographed while still weeping over it. Alice does not reveal what she overheard to Dan, even as he spends a year stalking Anna…