The U.S.S. Enterprise moves in to help after detecting a stellar core fragment heading straight for a human colony on what was thought to be a deserted planet. Picard contacts the colony's leader, Aaron Conor, with an offer to evacuate his people. But Conor refuses, telling Picard that evacuation would destroy his genetically engineered society. Instead, he insists on working to find an alternate solution, and reluctantly permits the transport of Riker, Geordi and Troi, the first visitors the colony has ever had, to help. Conor assigns Hannah Bates, a scientist from the colony, to work with Geordi. Riker beams back aboard the Enterprise along with Geordi and Hannah, who leaves the colony for the first time to work to save her home.

Back on board the Enterprise, Hannah is clearly fascinated by the ship's advanced technology. Meanwhile, Troi soothes a testy Picard, stressing the importance of working to preserve the colony's way of life despite the captain's disapproval of genetic engineering. Later, Hannah and Geordi discover that the technology of his VISOR can aid in steering the fragment away from the planet.

Troi returns to the colony and succumbs to her romantic feelings for Conor. The next morning, she sadly bids him goodbye, realizing that her DNA makeup would forever alter the colony's genetic balance. As she prepares to leave, Hannah and Geordi beam back to the planet with the announcement that they must transport fifty people to the planet in order to install the equipment necessary to deflect the approaching fragment. Knowing it is the only way to save his people besides evacuating them, Conor agrees.

With seconds to spare, Hannah and Geordi successfully alter the fragment's course and save the colony. But Hannah is hardly overjoyed by the news. Having encountered and worked with technology superior to her own, she decides she wants to leave the colony. In order to accomplish this, she stages a breach in the biosphere that would cause a necessary evacuation of her people.

Luckily, Geordi realizes what Hannah is doing and is able to avert the impending disaster. When Hannah explains her actions, Conor realizes he can no longer restrain her, and grants Hannah and all others who wish to leave the colony permission to do so. Twenty-three colonists, including Hannah, leave the colony, creating an irreparable balance in the society, and forcing Picard to wonder whether the starship's "help" was ultimately as damaging as a hit from the stellar fragment would have been.