The training room functioned as both a laboratory and a training center. It was situated inside the Imperial Tantiss Base, which itself was located on the planet Wayland. This facility contained a circular room, elevated above the rest, which was used for conditioning, torturing, and housing the Clone X trooper division's clone assassins. Beneath this room was a maze-like corridor leading to an elevator platform, providing a route to the upper chamber. To safeguard against intruders, several security measures were in place. These included ventilation shafts on the outside of the elevated room, designed to dispense a toxin developed by Royce Hemlock that induced unconsciousness upon inhalation. Additionally, a dynamic architectural system altered the labyrinth's layout, adding walls and platforms to disorient attackers.
Around 18 BBY, Royce Hemlock entered the room after a conversation with Clone Commander Scorch concerning the capture of genetically defective clone Omega. He then observed a clone assassin held within one of the pods. Later, during the skirmish on Wayland, Hemlock imprisoned the captured members of Clone Force 99 in the laboratory's torture pods. He initiated a conditioning process aimed at transforming them into clone assassins. However, Omega, Echo, and a group of clone troopers who had escaped from Tantiss Base's prison infiltrated the room and launched an attack on the Imperials. In response, Hemlock released all the assassins of the Clone X division (Sniper CloneX3, X4, and X5), who eliminated the majority of the invading clones. Hemlock then deployed the toxin, incapacitating the remaining clones. Nevertheless, Echo, protected by a TK stormtrooper helmet, resisted the gas and ascended to the elevated lab to assist Omega and the captured Force 99. Ultimately, Omega managed to free Wrecker from his restraints, who in turn liberated the rest of the Force, compelling Hemlock to flee the facility with Scorch and Omega.