After Snowbird gives Mike an Indian pony, Flash, in thanks for her work at the reservation Mike tries to enter the Territory Stakes Race, but race officials, Loren and Jake, won't allow a woman to ride. Dr. Cassidy arrives from Denver with his champion horse and spurns Mike attempts to speak to him colleague to colleague. Dr. Cassidy's rider, Drew, is injured and Mike diagnoses cranial compression, yet Dr. Cassidy refuses Mike's assistance. Drew dies and an angry Mike is determined to enter the race, disguised as a man. Meanwhile, with encouragement from Grace, Brian enters a pie-baking contest and is met with skepticism from Colleen and Loren. To everyone's surprise, Brian is declared the winner. Mike rides the race of her life and wins, but is disqualified when her disguise is revealed and Hank, riding Dr. Cassidy's horse, is declared the winner.

Dorothy, Loren's sister-in-law and old flame, is introduced as an abused wife who defends herself against her husband's assault, then seeks shelter with Loren. Marcus Jennings, Dorothy's husband, persuades Dorothy to return home with him, which she does. Later, they have another fight and Dorothy returns. Unfortunately, after the couple's last fight, Marcus is found dead, and Dorothy is the prime suspect. Mike defends her at the trial, but in the end Dorothy is found guilty. At the eleventh hour, Mike performs an autopsy on Dorothy's husband and proves Dorothy's innocence; Marcus was suffering from acute cirrhosis of the liver. Dorothy remains in town and Loren gives her a room at the General Store and helps her get started on her own newspaper, ""The Gazette."" Meanwhile, Snowbird, Cloud Dancing's wife, leaves Cloud Dancing's teepee when tradition dictates he take in a widow as his second wife.

Halloween is trick-or-treat for the residents of Colorado Springs when Sully's dead wife, Abigail, haunts Dr. Mike, after Sully suggests fixing up the homestead for her. Eventually, Mike is able to lay Abigail's ghost to rest. Meanwhile, Brian becomes terrified after his investigations lead him to believe Dorothy is a witch. But, later she helps him deal with his sadness about the fading memory of his mother. Jake and Loren's prank on the town backfires when Jake pronounces a man dead and his ""corpse"" walks away -- Mike later diagnoses the man as a catalepsy sufferer.

Jake, Loren and Horace are out hunting when Jake, mistaking an Indian for a deer, accidentally shoots and kills him. During the melee, Horace is wounded by an arrow, which Mike treats. Loren and Jake, frightened and guilty, try to cover up Jake's blunder by declaring that the Indians attacked. They persuade Horace to participate in this lie. Sully and Mike are caught in the subsequent hostilities between the Indians and townsfolk. The incident threatens to provoke an all-out Indian war, as well as a rift between Sully and Mike and between Sully and Cloud Dancing, until Mike elicits a confession from Horace and Sully intervenes to bring peace. Eventually, the Indian tribal council declares that Jake must make financial reparations to the dead Indian's family, including his horse, watch and ring.

Love finds visiting faith healer Sister Ruth, in the form of Kid Cole, who's revisiting the town in order to jail a desperado he's apprehended. The desperado's two brothers have followed him to town and stalk him. Kid Cole, strangely fatalistic, seems to have lost the will to live. Things come to a head when Mike and Sister Ruth must unite their mutual strengths; medicine and faith, to save Kid Cole's life. Mike performs an emergency procedure to evacuate the tubercular Kid Cole's lungs; Sister Ruth helps him find the will to live. Sully forces Kid Cole to reveal that Kid Cole feels terribly guilty for having gunned down the desperado's brother, who was unarmed. Sully helps the Kid resolve this crisis of conscience and in a climactic showdown, the town helps the Kid avert a gun battle with the desperados. Meanwhile, the Reverend refuses to allow Robert E and Grace to marry in the town church, but eventually capitulates to their demands, with some help from Mike and Sister Ruth.

Mike receives an emergency telegram from her sister Rebecca -- her mother is gravely ill. Mike rushes to Boston to her mother's side, the Cooper kids in tow, where Dr. Mike and her ""roughhewn"" children are met with raised eyebrows by Dr. Quinn's own family. While consulting with Elizabeth Quinn's attending physician, Dr. Mike meets a handsome and progressive Doctor, Dr. William Burke. Dr. Mike's prognosis of her mother (hepatitis) differs with Mrs. Quinn's doctor, Dr. Hanson, who diagnoses cancer. Dr. Burke, however, believes Dr. Mike may be onto something. They have a lot in common and develop a strong mutual admiration for each other. They work together to cure Mrs. Quinn and some of Dr. Burke's other patients. Meanwhile, Matthew chafes at being stuck in Boston away from Ingrid, while Colleen appreciates the learned and cultured atmosphere and Brian adores the candy stores. Just when everyone has settled comfortably into the Boston routine, Sully shows up, unannounced and in buckskin

Sully arrives in Boston and discovers that he's facing worthy competition for Mike's affection in the form of Dr. William Burke. Sully at first settles uncomfortably into Mike's Boston surroundings, but later, with prodding from the kids, submits to a grand makeover. Later, Sully romances Mike with dining and dancing, even attending an opera together. At an all-male medical society, Dr. Burke steps aside so that Mike can present a paper on Indian medicine, while Sully looks on. Afterward, Sully overhears Dr. Burke proposing marriage to Mike and heads back to Colorado, but not before confessing his love to Mike. In the end, Mike declines Dr. Burke's marriage proposal and Mike and the kids return to Colorado, where Dr. Mike returns Sully's declaration of love with a vow in kind.

Mike and Sully have trouble adjusting to the new status of their relationship, ""courtin'"". Sully introduces Mike to his world, taking her into the woods, showing her how to track and hunt. Mike pressures Sully into coming to a town meeting, where tempers flare over the scarcity of water. Later, Sully takes Mike to his home, a simple lean-to, and she wonders how they can make a life together when they're so different. Horace's attempts to divine for water fail, and Hank decides its time to pull up stakes and take Myra with him. Robert E and Grace also consider leaving. Mike and Sully persuade Cloud Dancing to share his methods for water conservation and farming with the town, only to be rebuffed by Loren and Jake. Loren and Jake take water from an Indian pond which Cloud Dancing warns is poisonous, but they sell the water to the townsfolk anyway. Everyone gets sick from the contaminated water and Dr. Mike must treat them. Afterward, the town pulls together to create a Thanksgiving feast

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

Mike is called away to Soda Springs to help with an outbreak of influenza and Sully promises to stay with the children. Sully plays ""Mr. Mom"" but the kids grow restless. While out exploring caves with Brian, Sully is shot trying to intervene between the Indians and the cavalry. When the smoke clears, Brian can't locate Sully and goes to town for help. The Reverend helps the kids hide Sully, who now has a bounty on his head. They take Sully to the cave for safety. Colleen enlists the Reverend's help to bring supplies from the clinic, but he is spotted by Hank and Jake, who are out for the bounty. They knock Hank out and tie him up, but when Colleen is forced to remove the bullet, she must employ Jake's assistance to save Sully's life. When finally they ride back into town, the Cavalry tries to arrest Sully for blowing up the railroad, but the townsfolk provide Sully with an alibi preventing his arrest.

Mike's Christmas Eve gets off to a bad start, triggering a personal crisis for Mike. Through no fault of her own, a patient dies of a heart-attack on the operating table as Mike performs a routine operation on Christmas Eve. The deceased man's family blames Mike. Later, at home, the Cooper kids bicker. Next, as Mike, Sully and the kids are on their way to the town's Christmas Eve party, Robert E comes to ask Mike to deliver a baby for a couple who's just come into town. The couple, married against their parents' wishes, are on the run. Robert E offers them the use of his stable for the birthing, as the couple's fathers, who're in close pursuit, will certainly find them at the clinic. Mike goes to attend the delivery, which causes her to miss the event.

Miners gather in front of Loren Bray's store to protest Loren's not extending credit to striking miners, and for doing business with the mine owners. A budding union leader, Conrad, is there trying to organize the workers. At the same time, Travis Stone, the mining boss, rides up, hands out flyers advertising for scabs. An angry miner throws a stick of dynamite onto Loren's porch, which Sully, who gets knocked out in the subsequent fray, comes to just soon enough to put out. Matthew takes a flyer -- decides he'll take the job to augment building costs on his homestead. By doing this, he's at cross-purposes with Sully and Mike, who try to talk him out of it. Grace tells Loren she won't be buying anything from him until the strike's over, due to his unfair trade practices with the striking miners. Matthew finds, to his dismay, that Loren charges 10 cents on every dollar of ""scrip"" (miner's credit) for ""bookkeeping"" costs. Later, as Mike administers some bicarbonate of soda (Brian's got a

Mike and Sully work to treat a typhus epidemic at Black Kettle's camp, which begins after Mike and Sully unwittingly convince Black Kettle to accept government blankets infected with the virus. Mike is heartbroken and guilt-ridden as she battles the tribe's typhus epidemic. When Matthew comes down with typhus, the town panics and locks the children in the clinic alone with Horace. Colleen treats Matthew and Horace contrives to send the kids out to the reservation to be with Mike. Meanwhile, the town prepares for the Fourth of July, ironically missing the point entirely that the first Americans, the Indians, are being systematically wiped out and further, that the newest Americans, the Immigrants, have just had their camp destroyed by the typhus-fearing townsfolk

A ragtag circus, consisting only of Heart and Atlantis, a mother-and-daughter team, arrives in Colorado Springs. Heart, the mother, enlists the townsfolk to participate as performers. Everyone accepts but Mike, whom Heart tries to engage as a trapeze performer. Later, in the homestead, Colleen reveals her fear of being in the limelight, and Brian asks Sully if he'll perform on the trapeze, per Heart's request. Sully says to Mike, ""I will, if you will,"" upon which Mike says she'll perform if Colleen will. Colleen reluctantly accepts the challenge. Heart engages the Reverend to be a magician, with Miss Dorothy as his lovely magician's assistant. Brian and Loren are the designated clowns. Colleen, Atlantis and Matthew do a tightrope act together, and Jake is pressed into service as the ring announcer. The town happily embraces their various roles in the circus, but friction occurs between Mike and Heart when Mike discovers that Atlantis, Heart's daughter, has webbed fingers. Mike wants to

Catherine, a beautiful blond woman captured by and raised with renegade Indians, is brought to Colorado Springs by soldiers when her tribe, which includes her husband, is wiped out, leaving her the sole survivor. She initially earns the townsfolks' sympathy, then their contempt when she rejects their gestures of kindness, doesn't know the language, and falls down into an epileptic fit. Indeed, her Indian name was ""Shivering Deer"" thanks to her grand mal epileptic seizures. Mike takes her in, but the only members of the family she trusts and feels comfortable with, especially with her faltering English, are Sully, then Brian. Brian, however, becomes decidedly less enamored of her when he accidentally glimpses Catherine kissing Sully. Later, when Brian confronts Sully, he doesn't understand Sully's distinction between ""being kissed"" and ""kissing someone,"" and troubled, tells Mike about it. Meanwhile, Jake, in a conversation with Loren and Dorothy about what marauding Indians do to white

Eight orphans arrive on the train. The Reverend takes them in at the church and Mike nurses their ailments. When no one in the town wants to adopt the orphans, the Reverend extends a proposal of marriage to Mike so that they can raise the orphans together. Mike briefly considers the offer, and Sully confronts her about it, asking her if she loves him. She accuses him of not making any kind of committment to her, whereas the Reverend has, to which he replies, ""If marriage is all you want...."" leaving his meaning clear without being spoken that he's possibly willing to offer more. Considering this, Mike turns the Reverend down, much to the relief of Sully and the Cooper kids. Eventually, the orphans board the train and leave town, but each orphan boards the train a more complete person as a result of their interaction with the townsfolk. Dr. Mike confronts the fact that she can't save the world and she and the Cooper kids emerge as a more united family.

A troop of black cavalry soldiers ride into town intending to cover themselves in glory by eradicating hostile Dog Soldiers who've been attacking the railroad. Mike commits an act of civil disobedience by tipping off the Indians, which results in carnage on both sides and the defeat of the Buffalo soldiers. She's accused of treason, and jailed, but the arrogant black cavalry leader, Sergeant Zachary Carver, manages to exonerate her when he's made to realize, through the combined efforts of Sully and Mike, that his beloved troops are nothing more than pawns in the U.S. Army's policy of genocide against the Indians. Returning the favor, Mike manages to medically fake the Sargeant's death, and he escapes court martial. Meanwhile, Colleen cheats on a test and by doing so manages to win a school trip to Washington. Mike must then explain the concept of ""good lying;"" that is, civil disobedience for a principle, and ""bad lying,"" that is, Colleen's self-serving actions regarding the test. In t

When Julius Hoffman rides into town and engages Matthew in a poker game, Matthew thinks he's found a great way to earn money to finish he and Ingrid's homestead, although Mike and Sully disapprove. At first, Matthew wins steadily, though he and Ingrid get into a terrible fight when, after missing an elaborate dinner she cooked for him (he was in a game), he confesses he used her hard-earned laundry money, which she gave him for building supplies, as a stake. Though Ingrid and Mike disapprove heartily, Matthew continues playing the game, even after he gets beaten up and robbed of his earnings. Eventually, townsfolk become so confident in Matthew's abilities that everyone but Mike, Sully and the Reverend back Matthew in the big poker game. The Reverend pulls Mike aside and confesses that he was once a gambler, knew Julius, and suspects that the town's been set up. As Matthew makes his way to the big game, Ingrid breaks up with him over his poker playing. In the process, she returns the e

Tom Jennings, Dorothy's son, shows up in Loren's store one day when Mike and the kids are there shopping. He's a Civil War Veteran with an old war injury -- his leg was almost blown off. Dorothy asks Mike to treat him when he complains of pain in his seemingly healed leg. She gives him a syringe of morphine for the pain, not noticing his blissful expression. Mike invites he, Dorothy and Loren to dinner. During dinner, Colleen develops a crush on him. Sully's suspicion is piqued when Tom leaves and he forgets to use his cane. The next day, Tom returns to Mike, telling her his leg hurts. She treats him, but denies him her last vial of morphine, which she's saving for an emergency. Later that day, Loren catches Tom slipping a vial of patent medicine from the store under his coat. When Dorothy confronts Tom, he replies that the pain just got to him, and complains that Mike won't give him any morphine. Later that night, he goes out and tries to mooch free drinks at the saloon. Later still,

Robert E buys a house in town. When the auctioneer, Jedediah Bancroft, sees that he's sold the house to a black man, he tries to renege, but Mike intercedes. Later, Mike is surprised to learn that Jake, Loren, Hank and Dorothy are displeased to have Robert E and Grace living in their midst. That night, at the homestead, Matthew tells Mike he's been invited to join a new men's club -- the Ku Klux Klan, which he knows nothing about but is heading out the door to investigate. At the meeting, Jedediah, the leader of the group, promises only ""a big surprise"" for the following night, then adjourns the meeting. The next night, townsfolk don white gowns, recite the KKK oath, and ride out to harass and beat Robert E. After treating Robert E, Mike storms into the barbershop, where she confronts Jedediah, Jake, Loren and Hank about the events of the night before. Jedediah tries to make offers to get Robert E and Grace out of town, even threatening Mike with the mortgage on her clinic if Robert E

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 and Sully get caught in the crossfire when, while visiting the Indian reservation, they see renegade Dog Soldiers shoot some Cavalry men. Mike is kidnapped in retaliation when the Indians discover she told Custer what happened; Sully vows to find her. Meanwhile, Brian falls in love with a horse Hank wins in a poker game.

Sully sets out to rescue Mike. Meanwhile, Custer takes the Indian reservation hostage, threatening to hang everyone unless Mike is returned. Brian works off the cost of the little horse; but Hank reneges on the deal, inciting Loren's wrath. Mike and Sully return to town just in time to keep the Indians from getting hanged. Hank, not anxious to pay double for all his goods at the General Store, delivers Taffy to Brian on his birthday, declaring that, ""Sometimes it's just good business for a man to keep his word.""

Mike and Jake go head-to-head when both campaign for the Mayorship of Colorado Springs. At issue: whether drinking and prostitution should be outlawed. Myra finally breaks loose from Hank.

Only the town's love for the infinitely unlovable Hank can pull him from the brink of a deadly coma. Meanwhile, Colleen and Brian tangle when Grandma Quinn sends Brian but not Colleen a present.

Mike is torn between two lovers when, in a blast from the past, her presumed-dead Civil War fiance, David Lewis, whirls into town to reclaim Mike from the arms of Sully, her current fiance. Also, Horace keeps ""losin' the mood"" when it comes time to consummate his marriage with Myra.