The Ga'Garen Codex, a grimoire, had existed for thousands of years by the time the High Republic Era arrived, and its enigmatic nature proved baffling to numerous linguists. Ultimately, this Codex found its place within the Jedi's Great Temple. Subsequently, after experiencing a troubling Force vision following the dedication of the Starlight Beacon space station in 232 BBY, Jedi Master Elzar Mann turned to the Ga'Garen Codex in search of understanding.
Mann's quest to unlock the grimoire's secrets spurred him to journey to Ashla, a revered moon orbiting the planet Tython, hoping to discover tranquility on its Isle of Seclusion. In 231 BBY, several months after the station's dedication, the Jedi Master reflected on how the Codex had been the catalyst for his journey to Ashla.
Cavan Scott penned the novel The Rising Storm, which features the Ga'Garen Codex. It was released on June 29, 2021 as part of Phase I of the Star Wars: The High Republic multimedia project. Prior to the novel's publication, StarWars.com included a reference to the Codex in a preview released on May 7 of that year.