Dune: Shaitan's Bargain

FOUR THINGS CANNOT BE HIDDEN - LOVE, SMOKE, A PILLAR OF FIRE, AND A MAN STRIDING ACROSS THE OPEN BLED. -FREMEN WISDOM

In  Shaitan's Bargain , who you choose to align with and the deals that you make can be just as dangerous as the desert itself. 

House Harkonnen are recruiting scouts and mercenaries to locate caves being used by the Fremen conducting raids on the spice harvesting operation in the Hagga Basin. The council of the poverty-stricken pyon village of Holfa takes a gamble on improving its fortunes by sponsoring the recruitment of agents on behalf of the Harkonnen, and the recruitment drive goes out around the village and beyond, even as far as Arrakeen. 

The player characters answer that call for reasons of their own, and learn that the mission is to map and explore the caves beneath Observatory Mountain and seek out where the Fremen may be hiding. The team must make an arduous trek through the Broken Land where heat, thirst and other desert dangers may threaten their task almost before it's begun. However, soon after arrival at the caves, a discovery and a meeting might change the outcome of the mission. 

Between House Harkonnen, the village of Holfa, and the Fremen, the conclusion of the adventure will depend on alliances and deals made, and which side (if any) the player characters have aligned themselves with. The fate of Holfa and its population lies in the hands of the player characters and how they choose to complete their business with the Harkonnen. 

This standalone adventure for  Dune - Adventures in the Imperium  is set before the arrival of House Atreides on Arrakis, but includes guidance on adapting it to other eras. The adventure includes a number of opportunities to influence NPC factions which, ultimately, affects the conclusion of the adventure. Although the threat of combat is never far away, it is possible to complete this adventure without resorting to violence.

You will need access to the game rules to play.  The Dune - Adventures in the Imperium Core Rulebook  has these rules in their most complete form. However, the  Agents of Dune  campaign box set also contains all you need to play.