From publisher blurb:
Durnab VII is a recently discovered world just beyond the borders of the Sonora sector. This strange world lives in virtual darkness all year round. It is the farthest populated planet from the star that it orbits. It orbits the star only once every 12312 days (using the 24 Sonoran standard hours as the measure).
Once every 12312 days the world gets daylight for exactly one hour before again plunging into darkness again.
During that brief amount of a time a flower is known to bloom called the brightshade plant. The petals of this plant are believed to have miraculous medicinal properties. The locals claim that it can sure just about anything.
Manager Leo Wang of the Aboleth Pharmaceutical Company approaches the travelers due to their well earned reputations as people who can get things done. He offers CR 200,000 for the travelers to visit Durnab VII and bring back the petals of three of these plants so that the company can analyze them for potential medicinal uses.