30-year-old single Mary Richards moves to Minneapolis to start a new life after a romantic break-up. There she reacquaints with Phyllis who rents her a room, and meets her upstairs neighbor and new best friend Rhoda. Mary unexpectedly lands a job as associate producer at the TV station WJM, where she works alongside her bristly boss, Lou; the comical newswriter, Murray; and the newscast's often-incompetent anchor, Ted.
Georgette gives birth at Mary's dinner party. With the hospital and doctor too far away, Lou and Mary help deliver the baby.
Mary decides to take a creative writing course, and is less than delighted with the criticism Lou levels at her efforts.
Sue Ann becomes deeply depressed when her sister arrives and gets an offer to do a competing homemaker show in Minneapolis.
Mary hires a new sportscaster who refuses to cover any sports but swimming and is faced with the prospect of firing her.
Ted suffers a heart attack on the air and for the next few days becomes conscious of how precious life is.
Lou promotes Murray to co-producer against Mary's wishes to prevent him from accepting a producer's job at a rival television station.
Ted and Georgette are initially disturbed to find that their son, David, is not doing well at school, but a psychiatrist's test shows that he is a genius. Unfortunately, David lets this go to his head and takes advantage of Ted.
Mary faces a contempt charge for not revealing her news source. Lou recommends a lawyer friend who takes a romantic interest in Mary.
Lou realizes that he has feelings for Mary's Aunt Flo, a journalist with a similar pride and passion in the news profession.
Lou learns from a source on the Teddy Award's panel that Murray will finally win an award for his news writing.
Mary is having trouble sleeping and resorts to pills, which has Lou concerned that she's become addicted to them.
Mary and Murray find it hard to believe that an attractive young journalist has tried to seduce Ted while they are at a convention in Hollywood.
Mary and Lou threaten to quit after the new station manager refuses to give them a raise.
A pompous but renowned critic is hired to provoke controversy on The Six O'Clock News, but the newsroom thinks he has gone too far when he begins attacking Minneapolis and its residents.
Ted and Georgette successfully audition for their own variety show, which becomes a big hit, but Georgette eventually finds that she would prefer being a wife and mother.
Sue Ann's Happy Homemaker show is canceled but she is determined to stay at WJM and asks Mary to give her a job in the newsroom.
WJM's former weatherman, Gordy Howard, returns to visit Minneapolis after becoming a highly successful network presenter in New York. Ted is desperate for a chance to join Gordy.
Mary happily accepts a date from a charming older man without realizing that he's Murray's father, but everyone else has difficulty coming to terms with the difference in their ages.
Ted offers Murray $200 to write an article on his behalf. The article becomes a success, but Ted refuses to share the credit with Murray.
Murray, Ted and Lou fantasize about being married to Mary.
Mary has planned a fancy party at her apartment, with a mystery guest of honor, but the power in the building goes before he arrives.
Mary has another disastrous date and worries she'll never meet the right man, until Georgette points out that every quality she seeks can be found in Lou Grant.
WJM-TV has some personnel changes in the executive department (again), and everyone except Ted Baxter is fired. The new station manager wants to see the WJM News the highest-ranked in Minneapolis, and for some reason feels that Ted can help him make it happen. (Seems a little odd, eh?) The gang says goodbye to each other in the form of a long, hard cry. Mary thanks them all for being her surrogate family, and Lou finally sentimentally says, ""I cherish you people."" They bravely march out the office doors singing, ""It's a long, long way to Tipperary."" At the last moment, Mary leans back through through the WJM-TV doors and turns out the light. So long, WJM-TV.