Horror mounts when a flu epidemic attacks Colorado Springs. Dr. Mike must attend the sick townspeople and protect others from getting the deadly disease. But being a lady doctor has people questioning whether she can handle the fatal epidemic.

A bitter Loren, who blames Sully for his daughter's death, tries to repossess Dr. Mike's cabin when he learns he still owns the deed.

As Dr. Quinn is trying to persuade the townspeople that smallpox vaccinations are necessary, the father of Brain, Colleen, and Matthew arrives.

Colleen and Becky become best friends when, at Bray's store, Alice, another friend, insists on taking Colleen's favorite fabric to make a dress for the Sweethearts' dance. Dorothy fears she may be pregnant when she faints in the general store. Mike assures her she is not, but she is beginning the ""change of life"". Later, Mike is frustrated when she tries to teach Sully to dance the Sweethearts' reel. Mike confides to Dorothy her fears about a physical relationship and Dorothy guesses Mike is a virgin. Meanwhile, Becky asks her new best friend, Colleen to ask Richard, a boy she likes, if he likes Becky. He asks Colleen if ""the girl,"" (he thinks it's Colleen) will meet him at the kissing tree. Colleen misunderstands, thinks he knows it's Becky. She tells Becky where to meet him, but Becky chickens out and Colleen goes in her place, to explain. Richard, assuming Colleen is there to meet him, kisses her. Becky finds out and is heartbroken. Becky and Alice team up against Colleen and spread

Rev. Johnson's in love with the town's new schoolteacher (Sherry Hursey), while Mike's concerned about the woman's wanton use of corporal punishment in the classroom.

Mike discovers a lump in Dorothy's breast and performs a mastectomy on her. Meanwhile, Colleen must deal with the unwanted attention of a new boy at school who fixates on her impressive bust. Finally, Jake, dressed in drag for Ladies Night at Hank's saloon, gets kidnapped and held hostage by an amorous outlaw, but escapes.

Dorothy insists the decision to have surgery is hers, not Mike's; Colleen finds the harassment unbearable.

Mike remains the sole voice of reason when townsfolk read a newspaper article predicting that a comet will end the world. Also, Mike addresses the Cooper kids' fears about ""the end."" Hank and Loren cash in on hysteria.

Mike loses custody of Brian and Colleen when their father, Ethan Cooper, arrives with new bride Lillian and reclaims them in a messy courtroom battle. Also, Myra and Horace are almost driven out of their minds by new baby Samantha's incessant crying.

Brian and Colleen run away from Ethan and Lillian, and Colleen contracts potentially lethal pneumonia, which, upon the kids apprehension, Mike treats. Also, surprisingly, Hank's the only person who can quiet Samantha, Myra and Horace's eternally crying baby.

Brian's homework assignment, an essay entitled, ""What Is Love?"" to be written in honor of Valentine's day, coincides with Dorothy and the town's production of ""Romeo and Juliet."" Also, Becky and Colleen compete to play Juliet, Dorothy and Jake split up, and Sully gives Mike an engagement ring.

When teen-outlaw Belle Starr robs the saloon, Mike takes her in, intending to reform her; Colleen overcomes her fear of riding. Belle Starr: Melissa Clayton.

Mike is overwhelmed with her new found passion for Sully, and feeling slighted, Colleen joins her schoolmates for dangerous and questionable escapades.

Feelings run high after a drifter is sentenced to hang for rape and murder

Dr. Mike's joyful reunion with a college friend soon turns competitive; Dorothy struggles with a new press.

Tales of her accomplishments embarrass Woman of the Year nominee Mike; Hank's grandmother visits.

Michaela has returned to work after being home with Katie. Between work, the baby and being so tired,Michaela is spread thin. Sully feels neglected. Sully helps Michaela through this difficult time. Colleen is accepted to college in Denver.

A malpractice suit prevents Dr. Mike from practicing medicine, leaving the reluctant Dr. Cook in charge.

A diptheria epidemic sweeps through C.S. Michaela performs a procedure that is not a proven cure. Becky (Haylie Johnson) dies.