Luanne's mother is released from prison and becomes romantically involved with Bill.
As Hank and Bobby proudly examine their new workbench inside the garage, Luanne exclaims that her mother, Leanne, has been released from prison. When Luanne is out of earshot, Peggy states that she will "tongue-kiss Bill" before she allows "that tramp" inside her home. A short time later, while discussing the latest news about Leanne with his friends, Bill accidentally drops a heavy table clamp on his foot. Hank pulls off Bill's sock, revealing crusty yellow toenails underneath. Embarrassed, Bill decides to see a doctor. Later, Peggy and Luanne discuss Leanne's past. Peggy warns that Leanne betrayed her husband by skewering him with a fork. But Luanne counters that her mother has given up drinking. Leanne is dropped off at the Hill home by a burly female trucker. Mother and daughter excitedly embrace one another, but Leanne receives a noticeably stiffer welcome from the Hills.
When Hank avoids offering Leanne shelter, Luanne proposes quitting school so she can find employment and rent an apartment with her mother. Unwilling to let this happen, Peggy reluctantly offers Leanne a place to stay. Hank is greatly annoyed when she transforms the garage into her new home. Meanwhile, Bill's foot condition is diagnosed as a common fungus.
A nurse tells him the ailment can be cured with pills...but he must avoid alcohol for them to be effective. A short time later, Bill encounters Leanne inside the garage. The pair--neither of whom can drink alcohol--hit it off, and the next morning Leanne and Bill stroll into the Hill kitchen dressed in bathrobes. Hank and Peggy can only stare, horrified at the implication. As an increasingly annoyed Peggy continues covering for Leanne whenever she fails to pay her daughter the attention and love she deserves, the romance between Bill and Leanne blossoms. But a hitch develops when Bill begins spending his money on gifts for Leanne instead of purchasing foot medication. One day, Leanne is repulsed at the sight of the yellow fungus on her lover's toes. She grows so unhinged that she downs countless bottles of beer, causing her expression to grow menacing. Hank discovers the emptied bottles, but before he can offer a warning, Bill announces that he and Leanne are engaged to be married. Angered that the secret has been revealed, Leanne slugs Bill in the arm. Hank attempts to warn Bill about Leanne's temper, but Bill reveals his love is moving into his home. Meanwhile, an increasingly frustrated Peggy tells Luanne that the next time Leanne breaks her heart, she will not come to her rescue. A short time later, the couple throw a pre-engagement party. When Leanne shows up drunk and belligerent, a desperate Luanne turns to Peggy. But as promised, Peggy turns away, leaving Luanne alone. The situation reaches a crescendo when Buckley insults Leanne as she gives him a lap dance. A furious Leanne grabs a fork, and just as she is about to thrust it into Buckley, she is stopped by Peggy. An all-out brawl ensues, during which Peggy gets the upper hand. Realizing she has been defeated, Leanne tells her daughter they are leaving. But Luanne chooses to remain behind with the Hills.