The arrival of the railroad brings surprises for Dr Mike and Sully's wedding day.

Dr. Mike's mother and sisters arrive with elaborate wedding plans; Gen. Custer places a bounty on Cloud Dancing, Sully's best man.

Dr. Mike and Sully remember the events that have marked their love affair and have second thoughts about their impending nuptials (featuring past episodes).

Sully must overcome his spiritual crisis in order to save Loren, who has been critically injured in the wilderness.

Sully and the kids try to help Mike deal with the emotional aftermath of the Washita massacre.

Mike and Sully arrive too late to avert Custer's slaughter of the Cheyenne Indians.

Substitute instructor Mike gets in trouble for teaching evolution theory; Mike takes an abused girl under her wing.

Dr. Mike and Sully try to stop a paleontologist who is digging up Cheyenne burial sites while searching for dinosaur bones.

After the visiting Belle Starr gets into a bar fight, she stays with Dr. Mike and disrupts her peaceful home life.

Mike's faith in Robert E. leads her to recommend him for the dangerous job of repairing a steam engine.

Passions explode when the townspeople start casting a production of "Romeo and Juliet"; Dr. Mike and Sully try to plan a day alone.

Brian and Colleen flee so their father won't be able to take them away from Dr Mike and Sully. Dr Mike realises she has to let them go after they're discovered and Colleen has pneumonia.

Mike and Sully attempt to adopt Brian and Colleen, but the arrival of their birth father and his wife complicates their plans.

Mike meets a kindred soul in an older woman who comes to climb Pikes Peak; Grace deals with her jealousy of Myra's pregnancy.

The townspeople spend what they believe will be their last days on Earth in a state of panic after a newspaper reports that a deadly comet is coming.

Appointed by the government to represent Indian rights, Sully learns his supervisor is selling goods intended for the Cheyenne to local merchants.

When an immigrant Jewish family arrives in Colorado Springs just before Christmas, the residents of town start to question what having the Christmas spirit means to them.

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

Dorothy ignores Mike's advice after finding a lump in her breast; maturing Colleen endures ridicule from boys.

Mike feels responsible for friends who were robbed on the Denver stagecoach; the kids prepare Thanksgiving dinner.

Mike's offer to pay for supplies needed to finish the new house threatens Sully's pride; Myra and Horace consult Mike about Myra's sleepwalking.

In Washington, Dr Mike and Sully struggle to find anyone who'll listen to them. Michaela tries to break Sully out of jail, after he's arrested for army desertion, and expose a conspiracy against the president.

Mike, Sully and Cloud Dancing head to Washington, D.C., to lobby on behalf of the Indians; Sully is jailed as a deserter; assassins target President Grant; Mike's life is endangered.

Dr. Mike performs experimental reconstructive surgery on a disfigured man.

Mike donates her father's book collection to start the town library, touching off a furor over censorship.

Matthew ignores Sully's advice about the land as he tries to prove his worth as a trail boss, but his inexperience endangers the lives of all those around him and leads to a stampede in which cattle are lost.

Matthew inherits a herd of cattle after Olive dies, and the townspeople help him drive the herd to Colorado Springs.

Loren plans a trip to Bolivia to prove he is not getting old; Brian seeks to prove his courage by camping out alone.

Dr. Mike and Sully disagree over the changes the railroad will bring to Colorado Springs.