While traveling in the Gamma quadrant, Kira, Dax, and Bashir respond to an automated distress call from a planet that the Jem'Hadar destroyed 200 hundred years ago. The attackers contaminated the inhabitants with a terminal disease that is passed on from generation to generation. The disease is called the Blight and when the afflicted is near death - called "The Quickening" - the disease becomes extremely painful. Bashir and Dax transport to the planet's surface to help find a cure but are hindered because of lack of trust by the inhabitant's of the planet. Bashir and Dax must not only win the trust of the people but also discover a cure to save the planet.