The Enterprise receives an emergency distress call from Rozhenko, currently posted to Boraal II, a class M planet in the process of an atmospheric catastrophe.
Upon arrival, the Federation observation post is found to be deserted, but force field shielding has been set up nearby which protects a series of caverns. In an effort to determine Rozhenkoâs fate, and aware that advanced shield technology is not indigenous to the planet, Enterprise Captain Jean-Luc Picard decides to send an away team to investigate. Concerned for his brother, Worf volunteers, and Picard orders him to go alone and be surgically altered to pass as a Boraalan so as to prevent any possible contamination of the planet's culture. Worf transports to the planet and discovers that his brother set up the shield to protect the local villagers he had been assigned to observe. While relieved that Nikolai is safe, Worf is concerned by what his brother has done and tells him that he has only postponed the deaths of the villagers.
Rozhenko meets with the shipâs senior officers in the observation lounge and describes his plan to save one village of the doomed planet by setting up a concealed artificial biosphere. Picard replies that there is nothing the Enterprise can do as regrettably the Federation Prime Directive prohibits any interference with the natural development of the Boraalan civilization.
After sadly witnessing the atmospheric dissipation extinction event transpire, the crew is puzzled by an unexpected power drain, the origin of which Worf tracks to the Holodeck. Going to investigate the cause, he finds that his brother has transported the population of the Boraalan village aboard the ship in direct contravention of the Prime Directive and Captain Picardâs wishes. Rozhenko has used the Holodeck to replicate caverns identical to those on the planet, misleading the villagers into thinking they are still on Boraal II.
Rozhenko tells Worf and Picard that he believes offering the Boraalan culture a chance of survival is more important than following the abstract concepts of the Prime Directive. He champions his updated plan of transporting the Boraalans to a new home on a different habitable planet without their knowledge, where their civilization can hopefully grow and thrive. Realizing that Rozhenko has given him no other choice, Picard reluctantly authorizes the plan and orders Chief Medical Officer Dr. Beverly Crusher and Operations Officer Lt. Commander Data to find a new home planet for the Boraalans.
Crusher and Data choose Vacca VI as a potential new Boraalan home world, but it is almost two days away at maximum warp. Shipâs Chief Engineer Lt. Commander Geordi La Forge tells Picard and Rozhenko that the Holodeck program may not run that long as the Holodeck and several of the ship's other systems were adversely effected by exposure to Plasmonic wave radiation generated by the atmospheric dissipation. Rozhenko volunteers to return to the Boraalans and help rationalize and account for any anomalies in the program which the villagers might witness. A mistrustful Picard orders Worf to accompany him, which Worf finds difficult as he is disgusted by his brotherâs actions and wants no more to do with him.
Returning to the Holodeck, Nikolai and Worf tell the Boraalans that they will lead them through the caverns to a new home far away from the old one. As they travel, Geordi gradually alters the program so that the terrain more closely resembles the slightly different environment of the new Boraalan home world. Several program errors do eventually occur, but the two brothers cooperate to explain them all away. Worf and Rozhenko have a further falling out and nearly come to blows when Worf learns that his brother has impregnated one of the villagers, and Nikolai tells Worf that he intends to remain with the Boraalans.
The situation becomes even more complicated when Vorin, the village chronicler, manages to find his way out of the Holodeck and suffers severe culture shock at the reality of the world outside. Enterprise Counsellor Deanna Troi and Picard try to help him adjust, offering him the choice of returning to his people or staying and making a new life with them on the ship. Vorin tells them he wishes to return to his people, but doesnât think he can live the rest of his life knowing and keeping the secrets he has learned, however he also realizes that his people will think him a liar or insane if he tells them the truth. Inside the Holodeck, Rozhenko is devastated by the possibility that Vorin might return and inform the other villagers of the reality of their situation, which would invalidate all the work he and Worf have done and destroy everything the villagers believe in. Ultimately Vorin canât live with what he has discovered and commits a form of ritual suicide.
The Enterprise finally arrives at the new Boraalan home, and ignorant of the fact that they have ever left their original planet, the Boraalans are beamed down to the eventual site of their new village. Worf and Nikolai finally make peace when Worf accepts and admits that the Boraalan race would not have survived if not for his brotherâs unconventional methods. Nikolai further assuages Worf by telling him that he is going to finally take responsibility by staying with his intended wife and the villagers and make his home with them as the new village chronicler. Worf replies that he will explain Nikolaiâs choice to their parents and convinces Nikolai to let him retain part of the chronicle as a souvenir.
Back aboard the Enterprise Picard muses with Troi that while their plan for the Boraalans worked out well, he is disappointed and saddened that Vorin wasnât able to bridge the gap between their two cultures.