In 9 BBY, a battle occurred at the Mountain Observatory on the planet Koboh between the forces of the Bedlam Raiders and the Galactic Empire. The raiders quickly gained the upper hand and the Imperials were no match for their forces, their leader the fallen High Republic Era Jedi Dagan Gera taunting the Empire using a Stormtrooper's comlink. Amidst the battle, members of the Stinger Mantis crew, including Jedi Knight Cal Kestis, traveled to the Observatory to confront Gera, having recently learned from Gera's Lieutenant Rayvis that Gera was planning to use an Abyss compass at the Observatory to navigate the Koboh Abyss and reach the planet Tanalorr hidden within. After taking down an entire Imperial garrison, Kestis witnessed dogfights between the raider's vuture droids and the Imperial's TIE fighters as his companion Bode Akuna attacked both in a Z-95 Headhunter.
Kestis fought his way to the top of the Observatory, facing warring stormtroopers and raiders along the way. He and Akuna eventually noticed that the skies were clearing after Kestis defeated Urgost, a raider known as the "Fist of Rayvis," and began to worry that Gera had found the compass. By the time Kestis and Akuna met up, the raiders had defeated almost all of the Imperial forces. After fighting their way to the top of the Observatory, Kestis and Akuna came face-to-face with Gera. Their meeting resulted in a lightsaber duel in which Gera used the Force to mess with Kestis's mind and confuse him by exploiting his fear. However, Kestis used this against Gera, making himself appear as Jedi Master Santari Khri, Gera's old partner, in the shared hallucination and killing Gera. As a result, the Abyss compass—though somewhat damaged—fell into Kestis and Akuna's hands, and the Jedi decided that they should use Tanalorr to host the Hidden Path network and train its operatives to fight the Empire. The two then left the Observatory, bound for the moon Jedha.