Set shortly before Star Wars Episode IV, this game stars twi'lek slave turned mercenary Rianna Saren, who is hired by Kyle Katarn to do work for the rebel alliance. On a mission to infiltrate a warehouse owned by the crime syndicate known as black sun she encounters an imprisoned security droid called Z-58-O (nicknamed Zeeo). Rianna frees Zeeo and together they end up forming the titular Lethal Alliance. Traveling to four different planets, Coruscant, Alderaan, Tatooine and Despayre Rianna and Zeeo work to track down Rianna's former owner, the ruthless Zarien Kheev. In the process they uncover a top secret imperial project to construct a new superweapon, known only as the Death Star.