A housewife sits on the stoop of her apartment building in a black neighborhood of Washington, D.C., and discusses all manner of things with her neighbors.
On the way home from running errands, Mary hits a BMW, breaking the tail light. From the persuasion of Rose, she decides to leave a note on the car. The next day, after no one has arrived to see the car, Mary wants to remove her note. However, another car comes by and nearly totals it, but then drives away. Before Mary can get to the car and remove her note, the owner comes out of an apartment and sees her note. Sandra tells Mary that she needs to use her "femininity" to get out of paying for the total damages. Mary says that she can't do that, so Sandra poses as Mary when the owner comes by to talk to Mary about the damages. Everything goes well until Lester comes home and their lie unfolds. Everything gets straightened out between Mary, Lester, and the car owner (Marvin), ending with a date for Sandra and a new friend for the Jenkins. Meanwhile, Mary tells Brenda that she cannot go skating with Calvin because she lied.
When Mary's brother Lewis comes to town on business, she decides to set him up on a date with Rose. The next day when Rose won't give Mary any details about the date, they get in to an argument where Rose finally admits that she thinks Mary's brother is "self-centered" and "egotistical". They stop speaking. Meanwhile, Lewis asks Sandra out on a date, and Mary fears that Sandra may be her future sister-in-law.
For an assignment that requires her to write about her "Most Interesting Relative", Brenda asks her parents for help. Lester suggests his aunt Lucy who was a woman brakeman. After Mary hears about Sandra's supposed relative who was a Moroccan prince, she searches through an old trunk to find information about an interesting relative of hers. What she finds is that she had an uncle, Corporal Mortecai Hurley, who was in the Civil War's 54th Infantry. She persuades Brenda to re-write her paper on Mortecai.
When Mary tries to convince the landlord to order her a new refrigerator, he refuses. Mary then agrees to loan Sandra her apartment for a extravagant party if Sandra will "persuade" the landlord to get Mary a new refrigerator.
News of the breakup of her neighbors' marriage has Mary worried that the same thing could happen to her and Lester. Mary plans an evening of romance for her and Lester. Lester buys flowers (at Mary's suggestion) and they try to force romance by going out to eat, dimming the lights, and playing romantic music. But they realize that they only think that works is by letting it happen naturally and reminiscing about the past. Meanwhile, Sandra has to babysit her 6-year-old niece Susie while her sister Harriet and her husband visits his sick mother. She solicits Mary's advice on what to feed her and how to get her to fall asleep.
When the landlord dies, everyone believes that Sandra will become the new landlord, including Sandra. She assures Mary that once she becomes the new landlord that Mary will have to find a new place to live after her lease runs out. The tenants all go to the will reading and it is discovered that he actually leaves the building to Rose. However, when Mary thought that Sandra would get ownership of the building, she called a building inspector to check out 227. He states that 227 is in need of numerous repairs, more than the tenants can afford.
The tenants have a sidewalk sale to pay for the repairs needed to fix up 227. Lester asks Mary not to sell his aunt's old, ugly lamp, but she does anyway, for $5. When Lester finds out, he is upset, but for more reasons than one. The lamp is where he hid the profits of the sale. The tenants get upset with Mary and outcast her. Luckily for her, the wife of the gentleman who bought the lamp comes by her apartment to give it back to Mary, because she did not like the lamp either. They buy it back from the couple for $50 and got the money back to save 227.
When Mary writes a letter to the President about the pothole that is on her street that no one has seemed to fill in 3 months, the secret service starts snooping around 227 and gets the residents nervous. Then they find out that the President was actually praising her for her consideration of her neighborhood. He makes plans to come to the street and refill the pothole with Lester. When the Jenkins' catch the city filling in the pothole, they stop them and tell them that the President and Lester will be doing that later. The President cancels his appearance because of an emergency meeting but calls and commends Mary and also flies over the street in his helicopter.
When Sandra tells Mary how she can't keep a job because of jealous wives, Mary asks Lester if he knows of any job openings. He admits that his company needs a receptionist for their main office and Sandra gets the job. However, Pearl and Rose worry Mary so much about Sandra working with Lester that Mary becomes suspicious and jealous.
Mary is upset that whenever Lester watches the football game, she doesn't get any attention. So she gets two tickets from Sandra for her and Lester to go to the game, with the hopes that he can teach her about the game and she'll get some attention. At the game, Mary insults the other fans and cheers for the wrong team. She and Lester end up having to leave early to avoid a fight.
Brenda desperately tries to get Calvin to notice her. When Mary doesn't seem to help Brenda out, she seeks romantic advice from Sandra. This ultimately upsets Mary when she finds out that Sandra alters Brenda's appearance.
Mary decides to buy a piano, even though Lester hates the idea and Brenda doesn't want to take lessons. When Sandra & Rose visit to take a look at the piano, Rose offers Mary piano lessons and Sandra wants lessons as well. Then, Sandra makes a sucker bet that for $20, she'll progress faster than her. After many piano lessons, Mary still struggles. Pearl tells Mary that Sandra used to take piano lessons. During a lesson, Mary offers to throw a party recital to show their progression. She shocks Sandra when she plays ""Minuet in G.""
When their church loses their land lease, the tenants must find another lot to place their church on. They enlist Lester's company's help to move the church to its new spot. Everything is ok, until the church comes up missing. Everyone is worried because they will have no place to have their Christmas pageant. They decide to build a large manger on the empty lot to hold the service. They later find out that the church was placed at the wrong lot.
Sandra starts dating a man who works with her and Lester, however she finds him boring. She leaves it up to the Jenkins to cancel their date. When he comes to the apartment, he meets Rose and she goes out on the date instead. The two hit it off very well. He asks Rose to go to New York with him and Mary and Sandra disagree on what Rose should do. Mary thinks she should not go, because they may end up sleeping together, which would be too soon for the time they were dating. Sandra thinks she should live life to the fullest. Rose finally decides to go and Mary apologizes for meddling into Rose's business. Rose has a great time but does not reveal if they went through it or not.
Pearl asks Mary if Lester would have a man-to-man talk with Calvin about sex and Brenda asks her parents if she could go to the dance Friday night. They believe that she is too young to date (14). From Mary's persuading, Lester talks to Calvin and ends his talk with, ""If you mess around with my daughter, I'll rip your head off."" Scared, Calvin breaks the date anyway. But Brenda still wants to go and comes up with a plan. Brenda tells her parents that she will go to the library Friday night, while Calvin tells his grandmom that he is going to see Haley's Comet. When Mary finds out, she goes to the dance and takes Brenda home. At home she and Brenda have a heart-to-heart talk, where Mary says she and Lester will relax the rules a little.
Pearl goes to Baltimore to visit her sister and the Jenkins watch Calvin for her. When he tries out for the romantic lead for a school play and doesn't get it, he becomes depressed. Sandra boosts his confidence and makes him feel better, however, he mistakes her kindness for affection and begins to fall in love with Sandra. When Brenda hears how silly Calvin is acting over Sandra, she goes and talks to him and expresses to him that she cares for him more than Sandra would ever, and she tells him that he is her best friend. Calvin gets over his crush really fast after that.
Lester's old boss comes to visit the Jenkins from Hawaii. While there, Rose hires him as the building repairman and lets him live an efficiency on the third floor. Pearl begins to notice that people go up to visit Lou and never return. She and Mary investigate and find out that Lou is homeless and his homeless friends are the ones that have come to live with Lou. It turns out his business in Hawaii went belly-up, and Lou lost everything. Mary has sympathy for them and feeds them, while trying to keep the news from Rose, because she would have to put them out based on the housing codes that they are breaking. Lester finds out about an abandoned building that his company will fix-up so the homeless people will have some place to live. This will also give Lou the chance to get back into business again.
While at a neighborhood watch meeting, the Jenkins get robbed, with Brenda in the kitchen on the phone. When they return from the meeting, they see that the burglars took an arm chair, their television, radio, and lamp. This gives Mary the idea of remodeling their living room. However, Lester has his heart set on buying a sports car. While on a test drive for the sports car, the neighbors and Brenda help set up a surprise for Mary. The living room has been remodeled with everything that Mary had circled in a decorating magazine. Lester decides that the sports car can wait.
At their vows renewal ceremony, Mary's parents are in the middle of the argument and are not talking to each other. Lester talks to his father-in-law, and Mary talks to her mother to encourage them to make up and go through with the ceremony. Meanwhile, Sandra meets a man who turns out to be married, and Rose has a peculiar conversation with another man: it turns out that both her late husband and his late wife both used to vacation in Vermont for one week out of the year, to go "fishing" and "writing poetry," respectively.
Sandra begins dating a basketball player who rubs Mary the wrong way from their first meeting. He comes across as rude and arrogant. Calvin idolizes him and mimics his attitude. Brenda doesn't like hanging around the ""new"" Calvin. When Calvin hears how the Rocketman talks to Sandra in an argument, and hears the Rocketman call him ""some dumb kid,"" he changes his opinion of Rocketman and realizes that he was acting like a jerk.
While reading the newspaper, Rose and Pearl choose 6 numbers related to an article that is in it. However, Mary thinks the lottery's a waste of time and money. But with a big jackpot, Rose & Pearl don't care. Mary preaches to the girls what a waste of time it is, so the girls agreed. Lester buys Mary a scratch off ticket and she wins $10. However, while waiting in line to redeem it, she gets a lottery play slip and gets numbers from the same newspaper article. Sandra spots her and then she know she's in trouble. Rose & Pearl enter Mary's apartment and were mad that after she preached about the evil of playing the lottery, she buys a ticket for herself. So she offers to split any winnings should it be a winning ticket. The Pick 6 is a winning ticket and that not only Mary won, but many people in the 227 apartment building won, as well as much of Washington DC! The big jackpot turns out to be worth $266 & that Mary, Rose & Pearl will each get $88.67!
When Calvin has a hard time finding a part-time job, Brenda and Pearl persuade Mary to convince Lester to offer Calvin a job working at the construction site. But when Calvin proves to be inept with his hands, he gets terminated. With some helpful advice from Mary, Calvin later lands five interviews.
