Joan returns from maternity leave and clashes with her mother about going back to work. She finds out her husband, Greg, has volunteered to return to war, and she tells him that if he leaves, he can never come back. He leaves. Now a single mother, she does what she can to survive, which includes agreeing to sleep with a man to land the Jaguar account, basically making herself a prostitute. Joan ends up as a partner in the firm, but her relationship with Don will never be the same.