Bill Henrickson seems like a typical suburban husband and father, except for the fact that he has three wives, seven kids and three homes to maintain. The Salt Lake City polygamist has to juggle his families' needs while overseeing his growing chain of home-improvement stores and attempting to reconnect with his fundamentalist relatives.
After being elected state senator, Bill Henrikson announces that he is a polygamist, and he and his families are attacked from every side; Alby Grant returns from living in the desert with the idea of purifying the compound and getting revenge.
After revealing his polygamy to the world the newly elected Bill goes even further out on a limb by calling publicly for more polygamists to come into the open while Barb talks Nancy, her mother, into attending a mother-daughter symposium.
Bill finds success in the Senate but finds new roadblocks set up by the Mormon church. Barb comes to a new conclusion about her life. Cara Lynn's adoption faces a new obstacle. Lois recalls her past with Frank.
Alby gets Adaleen on his side against Bill and his family. Rhonda asks Ben to marry her which results in Ben & Heather breaking up. Bill faces the possibility of a 20 year sentence, as his family tries to cope. Cara Lynn breaks down after Nikki tells her that Mr. Ivy never loved her.
In the series finale of Big Love, Margene plans on going on a cruise by herself to help people, Barb prepares to get baptized in the new church, and Nikki fears that she will be left alone if Bill goes to prison.