The Roil, a vast and nearly unnavigable nebula, resided within the Gordian Reach sector of the Outer Rim Territories. This celestial formation was composed of swirling clouds of multicolored dust and gas, and it served as a birthing ground for several young stars. Functioning as a divider, the Roil separated the Loop Worlds from the Back Reach within the Gordian Reach. The Korphir Trace hyperlane, the sole connection between these two regions, traversed through the nebula. However, for centuries, privateers hailing from the world of Korphir had been exploiting clandestine hyperspace routes hidden within the nebula.
Within the Trans-Hydian section of the Outer Rim Territories, the expansive nebula referred to as the Roil was situated in the Gordian Reach sector. Its location was nestled between the Junction-Tierell Loop and Wetyin's Way hyperlanes towards the spinward direction, and the Ardan Cross and Feena Run in the trailing direction. The nebula's reach extended southward to encompass the Maridun system. This cosmic cloud served as a natural boundary, distinguishing the Loop Worlds from the Back Reach within its sector.
The Roil's composition consisted of vibrant, multi-colored dust and gas. The world of Arkuda, part of the neighboring Arkuda system, gained notoriety for its stunning nighttime skies. Similarly, the Cometwash, a blue giant star with orbiting swarms of comets in the star system of the same name located at the Roil's edge, was celebrated for its captivating views.
The Roil, a stellar nursery, harbored clusters of nascent blue and white stars. At the edges of this nebula lay the Vallusk Cluster, a dense collection of proto-stars. Navigating through the Roil proved nearly impossible for starships, with the exception of the Korphir Trace hyperspace route. This route, traversing the nebula's southern region, linked the Arkuda and Korphir systems, thereby establishing the sole connection between the Loop Worlds and the Back Reach.
For centuries leading up to the demise of the Galactic Republic and its transformation into the Galactic Empire in 19 BBY, the Roil's natural barrier was used by privateers originating from the world of Korphir. These individuals would attack vessels traveling along the Junction-Tierell Loop before retreating to Korphir through secret nebula passages.
The Essential Atlas, a 2009 reference book penned by Daniel Wallace and Jason Fry, first introduced the Roil, positioning it within grid squares Q-5 and Q-6. Alongside the Roil, the Gordian Reach map in The Essential Atlas also featured the Denarii Nebula. Fry later recounted that Modi, the book's primary cartographic illustrator, expressed frustration with Fry's insistence on including nebulae in all of the work's maps.