Ally McBeal - Season 4 Episode 17
The Pursuit Of Unhappiness

Elaine cheated on Mark and now shes trying by all means to find a way for him to forgive her. She even takes advice from Richard! But in the end she has a serious talk with Mark and she tells him she cheated because he never fully trusted her. They break up. Meanwhile, Jackson is assigned to do the pre-nup for a rich, fat and bald man. Ally puts Larry to defend to soon-to-be wifes interests, which leads into a more personal dissension between Larry and Jackson. And Ling takes the case of a man whos being sued by his own son because a blood clot has left him perpetually happy which is ruining the family business.