While she may appear sweet at first, Nancy is highly manipulative and often has no regard for others feelings--including her husbands.
After Bill and Virginia both agree to bring in new partners to the clinic, Virginia is surprised to see that Bill has followed through and brought in Nancy, who is a former associate of Barton Scully's.
Nancy recommends that Virginia brings in Art Dreesen to interview for the position of her partner, without telling Virginia that she and Art are actually married. Virginia brings in Art and, after Lester Linden photographs Nancy and Art kissing, it is revealed that the two are married. While Bill insists that the two be fired, Virginia insists that they stay, partly because Art witnessed Virginia cheating on her nonexistent husband. Virginia also insists that the entire clinic be bugged. Art reveals to Virginia that he is in an open marriage with Nancy.
Art invites Virginia to Nancy and him's house to a party--a key party, which Virginia doesn't know, and brings Libby as a date. At the key/coat party, Art (knowingly) selects Virginia's coat and the two enter the bedroom together. They, however, do not have sex, but rather spend the night talking, and Virginia finally realizes she has feelings for Bill.
At the clinic, Virginia hears (via audio recording) that Art told Nancy that he had sex with Virginia. Virginia is furious and insists that Art tell Nancy that was a lie. After Art doesn't, Virginia forces him to, in front of Bill.
With tension building between Nancy and Virginia, Bill recommends that they switch up the partnerships, so Virginia is paired with Nancy. Meanwhile, after making a breakthrough, Bill gives Art a new study regarding homosexuality.
While Bill and Virginia are out of town investigating a rival business, Art and Nancy use the time to further their own studies with their own big clients. Nancy reveals that she wants to start her own clinic in New York with Art, and that she wants him to steal the homosexuality study.
Nancy reveals to Art that she is pregnant, and that she wants an abortion because she doesn't know who the father is. Art, however, doesn't want this and insists she keep the baby as he will father the child regardless of who the father is. Nancy nonetheless gets an abortion and Art listens to an audio recording of Barton and Nancy, with Nancy revealing that she knew the father was Art's and she got the abortion anyway.
Furious, Art goes to Bill and Virginia to reveal that Nancy is planning on starting her own clinic, and then leaves Nancy. Nancy is informed that legally she cannot set up a rival business. As an act of retaliation, Nancy finds audio of Art and Virginia on the phone discussing conversion therapy, and gives it to her old friend Barton, who was very against conversion therapy and the very idea of it, lobbing a grenade into Barton's relationship with Masters and Johnson.