Nightshade

After two hundred years of civil war the planet Oriana is dying. Most of the surface vegetation is gone, the air is nearly unbreathable, and the people themselves are wasting away. With hope nearly gone, the two warring factions have at last settled down to talk peace, and the "Enterprise" TM is sent to help them negotiate. Just after Picard, Worf, and Troi beam down, however, the ship is called away on another urgent mission, leaving them stranded alone with the Orianans, some of whom would rather not see a peace agreement reached. Picard is framed in a case of murder, and the negotiations fall to Worf.