For most galactic travelers, the planet Athiss barely warrants a second glance on the scanner. It appears to be nothing more than a small world off the Descri Wris hyperlane, with little of interest besides a scattering of unexplored ruins.
But the Jedi Archives tell a grim story. The Jedi Master Chamma visited Athiss early in his career and clashed with a dark side entity there. The duel, and the oppressive feeling of evil on Athiss's surface, drove Chamma close to the dark side of the Force. Shaken by the experience, he went into a self-imposed exile; it was almost a century before he came to terms with what he had seen and felt on Athiss, and was able to return to the order.
The many ruins on Athiss have never been properly studied. They resemble the architecture of the ancient Sith Empire, but their purpose is mysterious. A few records of Athiss survive in the libraries of the Citadel, but contemporary Sith scholars are forbidden from studying them, on the personal order of the Emperor.