Eric enlists the help of a neighbor to stop Matt from smoking, and makes a vain attempt to help Lucy deal with her flowering womanhood.

Matt helps out an elderly neighbor, but winds up getting in hot water for it; Eric searches for a way to aid a proud but homeless family; Lucy's 13th birthday approaches and she wants a party.

Mary undergoes knee surgery, while Matt learns that Michael Towner was the hit-and-run driver; Wilson reveals the truth about Billy to Eric.

One of the members of Eric's congregation, Mrs. Bink persuades him to investigate the real reason of why her best friend Mrs. Hinkle is moving into a retirement home. Meanwhile, Simon and Ruthie are performing an experiment and are trying to convince Matt that Simon is shrinking, but the tables suddenly turn for Simon. Also, Lucy tries to get to the bottom of one of her classmates, Shelby as she is rumored all over school of being bulimic.

As Annie plans a mysterious day of cleaning as Eric discovers the shocking news that Mary ran away from ""The Colonel""'s to come back home because of a devious scheme she had with Robbie and freaks out. Eric is convinced that more trouble is brewing and goes to insane lengths to find answers. In reality, Mary is heading home for a huge surprise birthday party for Eric, attended by all the people whose lives he's changed for the better in the past few years. Chores at home are interrupted, however, when Ruthie discovers Frankie and Johnny's baby, Mercy at the Camden front doorstep. Meanwhile, Lucy stays with her friend Mike's (guest-star Jeremy Lelliot) near catatonic mother for the day, and drops a proverbial bomb on Lucy. Also, Matt and Simon try to figure out why they delivered Mrs. Bink (guest-star Eileen Brennan) to the hospital.

Reverend Camden and Chandler enlist the help of Ms. Bink to raise money for the church's leaky roof, but it turns out she needs a little help of her own. Meanwhile, Ruthie's boyfriend Peter suspects that his mother's new boyfriend has some secrets to hide; and Lucy and Roxanne have a girls' night out on the town during which Lucy shares intimate details of her newlywed life. Meanwhile, the twins steal money from their parents' bedroom and from a coffee can in the kitchen.

Eric and Annie throw a "Welcome to the Neighborhood" party for Ruthie's Muslim friend Jill Dupree and her parents, but the Duprees are hesitant to attend. Eric is shocked and disappointed when he learns that his neighborhood is not a friendly place for Muslims. Meanwhile, Cecilia's house is robbed while she and her dad attend Kevin's first Neighborhood Watch meeting; Roxanne mentors a troubled sixteen-year-old and suspects that he might be involved in the robbery, and Chandler finds himself attracted to Peter's mom Paris.

Annie's half-sister Lilly is getting married and wants their ailing father to walk her down the aisle but Annie worries that the strain might be too much for him. Meanwhile, Fred and Mrs. Bink attend premarital counseling with Chandler, but Fred's mother tries to put a stop to the wedding because she thinks Mrs. Bink is a gold digger. Lastly, Jimmy and Pat, two mentally challenged people, decide to get married after just one date and ask Chandler to perform the ceremony, but Jimmy's parents try to put a stop to it.

Racism comes to light at the high school when Alex, a new African-American student, wants to give a report on Dr. Martin Luther King, but his teacher argues that they have already covered that topic in class. When Martin inadvertently supports Alex's case, he falls victim to a hate crime. His car is defaced with racial slurs, and he refuses to wash it off until the culprit is caught. Meanwhile, for her own report, Ruthie attempts to recycle an essay that she wrote three years ago.