As Bill prepares for the opening of a new addition to his hardware store chain, he receives bad news about his father's health, and also deals with trying to balance the needs of his three wives.

While Bill seeks protection against the religious compound led by Roman Grant, things heat up between the sister-wives over Margene's overtly sexual behavior. Roman "The Prophet" asks Bill's father to act as a go-between to deliver a message to his son, and the Hendricksons get together for a family dinner with Bill's business partner and his three wives. Meanwhile, Margene pressures Bill about buying her a car and Ben goes out on a date with a girl that seems too mature for him.

Bill gets a new home security system, Nicki throws a birthday party, new neighbours move in, and Margene meets her mother-in-law. Meanwhile, there's a break-in in Bill's hardware store.

Bill goes on a hunting trip with his son Ben, Barb tries to get accredited as a full-time teacher, and shopaholic Nicki realizes she can't pay her credit card bills. Meanwhile, Sarah goes to a house party but ends up needing her friend Heather's help.

Nicki suspects that Bill is having an affair and is considering bringing a fourth wife to the family. Margene, feeling alone in the big house, befriends the new neighbor, Pam Martin. Bill goes after Roman and tries to expose him, but polygamy accusations also fly in the Home Plus. Meanwhile, Ben is trying to cope with his arousing sexuality and being a teenager.

Bill attends the funeral of Frank's first wife Roberta at Juniper Creek, and strikes a deal with Roman. With Roberta out of the picture, Bill's mother Lois attempts to rise up on the social ladder at the compound, and Barb and Nicki find themselves in a hairy situation at Henrickson Home Plus.

Bill considers running an expensive advertising campaign, Barb finds out about Nicki's secret, and Margie goes to church with Pam, their neighbor. Meanwhile, Sarah brings home a surprise guest, and Ben goes on a trip with his friends.

Bill and Roman's disagreements result in lawsuits from both sides as well as unwanted houseguests from the compound. Sarah learns about her family's history from her grandmother and Joey confides in Barb.

Bill wants to throw a party to celebrate Don's plans of getting a fourth wife but Nicki's massive credit card debt weighs heavily on his mind. Pam's friend attempts to make his moves on Margie, but she is preoccupied with wanting to know more of how she became a part of the Henrickson family.

The Henrickson's prepare Teenie's baptism with friction and surprises from Barb's judgmental sister. Bill decides to take preemptive action against Roman with his brother. Margene continues to butt heads with Nicki, and her misfortunes pile up. Ben wants to show his affection to Brynn but is surprised when she demands something more.

Both Bill and Barb get social recognition as Barb is selected as a finalist for a "Mother of the Year" award and Bill is asked to become a member of the Salt Lake City Leadership League. Meanwhile, the sister-wives draw up their wills, and Rhonda gets to know what life outside the compound is like for teenage girls when she hangs out with Sarah and Heather.

To Roman's surprise, Bill and Joey attend the UEB priesthood council meeting. Alby's visit to Wanda brings out her old habits, which could potentially land Bill in a big trouble. Rhonda uses the acting competition as an excuse to leave the compound but she discovers that her family isn't willing to let her go. Finally, Barb attends the Mother of the Year awards ceremony but not all goes as expected.

After they're outed as polygamists, Barb decides to leave the family while Bill starts an investigation of who leaked the information. Meanwhile, Sarah attends a support group for ex-Mormons

Nicki goes back to the compound for a family reunion, bringing Bill with her, where they find out the extent of Roman's betrayal of their family. Barb is annoyed by Margene and Ben's behavior. Meanwhile, Alby disobeys his father.

Bill and Roman butt heads when Rhonda disappears from the compound. The prosecutor offers Joey a plea bargain in exchange for a confession. Meanwhile, Sarah takes an interest in a boy from her support group.

Margene's mother visits the family. Scott has upsetting news about Alby. Meanwhile, a familiar face returns to Juniper Creek.

Bill is stressed out by work, and Frank tries to get a hold of Lois' money. Meanwhile, the family discovers Ben and Brynn's secret.

Bill seeks his wives' advice regarding the video poker business. Barb tries to reconcile things between Sarah and Heather. Meanwhile, Lois seeks revenge on Frank.

Bill takes Margene to a convention. Frank is looking for a new wife. Meanwhile, Nicki throws a party.

In the season finale, the family prepares for the annual Pioneer Week. Bill and Alby butt heads over the control of UEB. Meanwhile, Margene reveals the truth to Ana.

With the grand opening of the Blackfoot Magic Casino only days away, the Henricksons make last-minute preparations. Meanwhile, the feds probe the whereabouts of Roman Grant; Adaleen shares a shocking secret with Nicki; Margie makes an on-air slip-up; Bill and Nicki's smarmy ex, J.J. Walker, work out an arrangement allowing Cara Lynn to stay at the Henrickson's.

Ignoring pleas from Nicki to become Juniper Creek's next prophet, Bill contemplates running for the vacant Utah State Senate seat. Joey and Wanda return to Juniper Creek, but a suspicious J.J. is lurking. Sarah and Scott forgo a wedding in Bill's church in favor of a civil ceremony, shocking Barb. Margene confronts Nicki about her feelings for Ray Henry.

Bill, Nicki and Cara Lynn travel to Washington, D.C., where Bill tries to land an endorsement from Congressman Clark Paley while mending things with Nicki. Meanwhile, Margene's on-air triumph is tempered by a case of mistaken identity; Joey goes to extremes to safeguard a secret; and Barb and Sarah hit a young Native American woman with their car.

Pressed by Coburn to state his intentions, Bill gets his family to stage an elaborate rally announcing his candidacy. He isn't so lucky when an audit uncovers insurance discrepancies caused by his multiple wives. To protect his secret and save his candidacy, he ends up asking Don to take the fall, and moves up his announcement by three days.

Bill pulls out all the stops to win Paley's support for the State Senate nomination, while Nicki continues as his campaign's 'secret weapon.' Meanwhile, Margene gets the cold shoulder; Marilyn pitches to represent the casino's interests in Washington; Frank picks a bad time to drop by the casino; and Bill absorbs a last-minute sucker punch from Coburn.

Ana resurfaces with a surprise revelation. Meanwhile, Bill tries to get Tommy and Jerry to rebrand the casino; Marilyn makes yet another impressive pitch; Lois and Frank take Ben and Jodean south of the border; Nicki is infuriated by Alby; Margene worries about her booming business; and, with a flourish, Bill shows his wives the family's collective future.

With a revenge-minded Joey in tow, Bill makes an emergency trip to Mexico after Lois and Frank's latest smuggling escapade backfires. Nicki is jolted by a doctor's news, but even more flummoxed by Adaleen's shocking revelation. Margene offers up a novel remedy to keep Ana from leaving the country with her fiance, Goran. A bomb scare rocks the casino.

Sarah makes an announcement that shakes up the family; Nicki tries a new look; Margene is put on the defensive when Bill questions her real reasons for getting married. An ill-timed remark puts Barb in an unwanted spotlight; an exposed Marilyn looks to bring down Bill; Bill looks for clues about J.J. in Kansas, while Adaleen finds them closer to home.

With the election only days away, Bill puts the squeeze on Paley to protect his candidacy. But Marilyn has an ace up her sleeve that threatens to wreck Bill's chances. Meanwhile, Nicki gets news that seems too good to be true; and a late-breaking polygamist scandal forces Bill and his three wives to rethink their bold post-election plans.

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.

The Henricksons' holiday cheer is tested by family revelations. Alby's purification of Juniper Creek leads to a defection.

Bill fights for his right to be sworn in as senator; Barb, Nicki, and Margene struggle with personal revelations and changed public profiles.

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.

Bill refuses to give in to Barb's vision of the church; Nicki chafes at the status quo; Margene looks to rally the children of polygamy.

Bill eyes a wedding as a chance to reseal his commitment to his wives; Alby makes a game-changing power play.

Bill fights for his family and his freedom; Alby looks to settle unfinished business; Nicki plans a new future for Cara Lynn.

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.