When Sully is offered a job helping to survey the new National Park at Yellowstone in Wyoming, Dr. Mike is faced with the prospect of leaving her practice and all their friends and moving into the wilderness. With Sully no longer acting as the local Indian agent and banned from the Indian reservation, Dr. Mike realizes that it is important for him to have work that is meaningful to him. Leaving everything and everyone she knows and taking their new baby into the wilderness, however, is a daunting prospect for her. Meanwhile, as Matthew and Emma think about marriage, Brian agonizes about his first date at the Sweethearts' Dance, and Dorothy teaches Cloud Dancing some ball room dances while he provides her with background on Indian customs for a book she is writing.

Dr. Mike matches wits with a notorious Indian hater, Maj. Samuel Morrison, as she tries to mediate a peace treaty between Black Moon's braves and the cavalry, which would include a pardon for Sully and allow him to return home. Dying of consumption, Black Cloud agrees to surrender if his braves are allowed safe passage to the reservation. Wellend Smith, an emissary sent by President Grant, sides with the Indians, but Maj. Morrison is determined to thwart the agreement and put them in prison. Mike and Sully must look toward Sgt. McKay for support in upholding the law

After accompanying Black Moon's braves safely to the reservation, Dr. Mike and Sully begin the trip home for Christmas but are delayed when they stop to help a hapless young married couple they find wandering in the wilderness. The young couple, Chester and Hallie, are former city dwellers trying to find a new settlement established by their relatives, but are hopelessly lost. Meanwhile, Daniel, who has been wandering all his life, is tempted to give up his job as sheriff to accept an offer to run a mining operation far away from Colorado Springs.