Adan’s small hydrosphere is entirely located in a single deep sea called the Cleft. From that sea grows the Clench, a writhing mass of plant life that extends far into the desert, providing life-giving crops for the world’s six million people. Unfortunately, the Clench is dying and the only people who can help are a remote community of psionic exiles living in the deep desert. The people of Adan have come to terms with their presence, but a scientific team from an Imperial Research Station has come to the planet to find the psions and strip them of their psionic abilities using a controversial new technique. If they succeed, all of Adan might very well pay the price.

Errant Lightning includes:

• World and city maps of the exotic world of Adan
  
• The Scirocco, a tilt-rotor aircraft
  
• New psionic talents
  
• New vehicle designs that take part in a climactic battle deep in the desert