Defense of Rishi Station

The Kaminoans, the indigenous inhabitants of the extragalactic planet of Kamino, possessed advanced cloning expertise. This expertise led to their recruitment by Jedi Master Sifo-Dyas. Sifo-Dyas, acting secretly against the wishes of the Jedi High Council, decided to ensure the Galactic Republic possessed a military for the war he had foreseen in his visions. Consequently, Kamino became a crucial military objective for the Confederacy of Independent Systems during the Clone Wars. Numerous sensor outposts were established to monitor potential Separatist attack routes to Kamino.

One such outpost was Rishi Station, located on the desolate Rishi Moon. Despite its strategic significance, many of the clone troopers posted there, primarily inexperienced rookies fresh from training, found their assignment incredibly monotonous. The station was under the command of combat veteran Sergeant O'Niner, who consistently emphasized the vital role Rishi Station played in Kamino's defense. Among the troopers stationed at the base were the members of the training group Domino Squad: Hevy, Fives, Echo, Cutup, and Droidbait. Hevy was particularly vocal about his dissatisfaction with the uneventful posting, expressing a strong desire to fight on the front lines.

Following the Battle of the Kaliida Nebula, but still in the early stages of the war, the Separatists initiated a plan to attack Kamino. The assassin Asajj Ventress had already infiltrated the ocean planet. Simultaneously, General Grievous intended to deploy a force to eliminate the clones at Rishi Station and manipulate the station's all-clear signal. This manipulation would prevent the Republic from detecting his approaching invasion fleet. However, at the same time, Commander Cody and Captain Rex were conducting an inspection tour of various remote Republic military installations. After inspecting the tracking station on Pastil, the Rishi moon was their next destination.

Concealed by a meteor shower that prompted Rishi Station to activate its deflector shields, a squad of BX-series commando droids descended to the Rishi Moon aboard Droch-class boarding ships. CT-327, a deck officer, spotted one of the vessels shortly after it landed. However, before he could report the sighting, the droids ambushed and killed him. Inside the station, Sergeant O'Niner discovered he couldn't contact the sentry. After Fives informed him that CT-327 was absent from the scope, O'Niner dispatched Droidbait and Nub to investigate. They arrived at the entrance hallway to find the commando droids had just breached the doors. They only had time to report the droids' presence before being shot and killed.

O'Niner grabbed a blaster and engaged the droids, instructing his troopers to attempt to send a signal to command before he, too, was killed. However, the droids had already disabled the station's beacon from the outside. Cutup destroyed the door controls to the control room to delay the droids, as the troopers knew they had to disperse. As the commando droids began cutting through the door, Fives, Echo, Hevy, and Cutup escaped through a ventilation shaft leading to an area beneath the station, although Hevy was hesitant to go. Upon being informed of the remaining clones' escape, the commando droid captain dismissed them as "cowards" before declaring their insignificance and ordering the hardwiring of Rishi Station's all-clear signal.

Shortly afterward, the Nu-class attack/transport shuttle Obex, carrying Commander Cody and Captain Rex on their inspection tour, entered the Rishi system. When the starship hailed Rishi Station, the commando droid captain donned a clone helmet and manipulated its vocabulator to mimic a clone trooper's voice. It attempted to dissuade Cody and Rex from conducting an inspection, further undermining the impersonation by ending the transmission with the well-known Separatist battle droid phrase "Roger, roger." Now realizing something was amiss on the moon, Cody placed Rex in charge of the operation.

Fives, Echo, Hevy, and Cutup emerged from the ventilation pipe some distance below Rishi Station. Cutup was immediately seized and devoured by a passing Rishi eel, horrifying his squadmates. Fives fired at the eel with a DC-17 hand blaster he had taken from the station, but it had no effect. Soon after, the rookie clones observed the Obex approaching for a landing. Aware of the danger the inspection team was in, they attempted to contact them, but Echo was unable to reach them because the officers' comlinks were on a different scramble setting. Upon disembarking from the shuttle, Cody and Rex carried additional DC-15A blaster rifles. They were soon greeted by a commando droid disguised in clone trooper armor that emerged from the base. The commando droids had prepared an ambush on the landing platform in case they failed to deter the officers from landing. The "trooper" tried to convince Cody and Rex that everything was normal at Rishi Station, but the unnatural body language and the absence of an on-duty sentry raised suspicions. The two officers demanded to be taken to the commanding sergeant.

Below, after Echo reported his inability to reach the inspection team, Fives used a droid attack flare he had with him. Upon seeing the flare, Rex immediately shot the "clone trooper" in the head, removing the helmet after Cody's protest to reveal the commando droid underneath, as he had suspected. The other commandos on the platform then revealed themselves and attacked, forcing Rex and Cody to retreat down the platform. When the droids threw thermal detonators down the platform towards the clones and the attack shuttle, Rex decided it was best to retreat off the platform entirely. While the droids assumed Cody and Rex had been killed by the subsequent explosion, which destroyed the Obex, both officers used ascension cables to descend from the underside of the platform to solid ground. They quickly encountered the three survivors, and Rex, remembering the commando droids' impersonation abilities, held the rookie troopers at blaster-point and ordered them to remove their helmets, much to their confusion. After Fives, Echo, and Hevy removed their helmets, the Rishi eel from earlier reappeared, only to be killed by Rex with a single shot to the eye. Afterwards, the clones were introduced to each other, and the officers identified the three as "shinies" due to their lack of combat experience, although Rex expressed hope for Hevy when the trooper stated they were ready to retake their base.

The five clones scaled the cliff face towards the station. With the blaster rifles Cody and Rex had brought from the shuttle, Rex's own blaster pistols, and the pistol Fives had brought from the station, there were enough weapons for each trooper to have one. Rex's plan to open the station's blast doors, which Cody doubted, involved eliminating and impersonating the droid sentry on duty outside the base, a task the Captain undertook himself. The droids just inside the doors, not noticing Rex's customized armor, mistook him for the sentry when they saw him approaching through the camera of the TT-8L/Y7 gatekeeper droid in a deliberately stilted manner. Rex answered all their questions with "Roger, roger," although the droids noticed his voice was slightly different from a commando droid's impersonation of a clone and assumed there was something wrong with the sentry droid's vocabulator. When asked to remove his helmet to prove he was a droid, Rex held up the detached head of the destroyed droid sentry to the camera, crouching below it. The droids also failed to notice that their comrade's eyes were not illuminated to indicate activity. The ruse succeeded in opening the door, and the three droids on duty at the door were quickly destroyed by the clones.

With Rex leading, the clones then stormed the station's control room, eliminating all the commando droids present. The droid captain attacked Rex after he shot the blaster out of its hands, but Rex dodged the vibrosword strike and broke the droid's neck before slamming it into the floor. It was soon discovered that the droids had hardwired an all-clear signal, preventing the clones from contacting the Republic about the situation.

Shortly afterward, Grievous' fleet arrived in the space near Rishi. The clones spotted this from the control room window. Grievous attempted to contact the commando droids, but receiving no response, he dispatched a C-9979 landing craft with reinforcements to Rishi Station. Having run out of time to repair the hardwired all-clear signal, Rex decided the station should be destroyed to cut off the broadcast and warn the Republic. He requested every thermal detonator in the base's inventory. When it was pointed out that detonators would not be powerful enough, Echo suggested the highly volatile liquid tibanna, used to heat the base, as an alternative explosive. While Cody, Hevy, and Fives went to the armory to secure weapons to defend the base, Rex and Echo moved the liquid tibanna, stored in PLNK-series power droids, into the control room and began setting them up to explode.

When the Separatist reinforcements attempted to enter Rishi Station, they were met by Hevy, wielding a Z-6 rotary blaster cannon and quipping that the droids hadn't said "please." Cody and Fives quickly joined him, and the three eliminated the initial wave of B1-series battle droids before retreating inside and resealing the door. In the control room, however, Rex and Echo were experiencing technical difficulties with the detonator, as the handset they intended to use to detonate the tibanna remotely was not linking up to the detonator attached to the tanks. Running out of time as the droids blasted open the main door, Rex asked Hevy to examine the detonator, which he promised he could fix quickly. As the others retreated down the ventilation shaft, Hevy, struggling to fix the problem, decided to stay behind and ensure the bomb detonated, even at the cost of his life. He hid in a hallway near the control room.

Entering the control room, the battle droids assumed the clones had retreated out of cowardice, paying no attention to the plonk droids. After the other clones had emerged from the ventilation pipe, Rex attempted to order Hevy to detonate the bomb, only to discover he was not present. He immediately contacted him by comlink to order him to escape the base. Hevy refused, insisting he knew what he had to do, and engaged in a fight with battle droid forces as he attempted to return to the control room. During the fight, he was wounded after being shot in the shoulder. As he headed down the hallway to the control room, his blaster cannon jammed, and he eliminated a few more droids by throwing the now-useless weapon. Hevy was shot twice more in the back as he neared the detonator, and dragged himself over as he was surrounded by enemy droids. One droid asked if they took prisoners, and Hevy responded that he didn't before detonating the bomb, killing himself and destroying Rishi Station. Outside, Cody, Rex, Fives, and Echo took cover from the falling debris, and Echo remarked that Hevy had always hated the base.

Aboard the Venator-class Star Destroyer Resolute, Jedi Generals Anakin Skywalker and Obi-Wan Kenobi, along with Admiral Wullf Yularen, had received Cody's report of his and Rex's visit to Pastil. However, when the two officers failed to check in from the Rishi Moon, both Jedi grew concerned, Kenobi moreso. Although he quipped to his former apprentice Skywalker that perhaps his tendency to disobey orders was being picked up by Rex. Kenobi was also concerned about Skywalker overreaching himself in his obsession with locating Grievous. However, the fact that Rishi Station was still transmitting an all-clear signal suggested to Kenobi that there was likely not a serious problem.

When the destruction of Rishi Station stopped the all-clear signal, Kenobi, Skywalker, and Yularen, concerned, mobilized their fleet to immediately rush to the scene. On his flagship, Grievous was outraged, not having wanted his troops to destroy the station, and berated a battle droid who suggested the destruction was a good thing. The arrival of the Resolute and its sister ships forced Grievous' outgunned fleet to retreat.

LAAT gunships were dispatched to the Rishi Moon to sweep the area, and Cody, Rex, Echo, and Fives were picked up by the Crumb Bomber. Subsequently, Fives and Echo received medals for their service in the battle and were inducted into the 501st Legion. Both troopers were unsure if they deserved the honor, but Rex and Cody reassured them that they had earned it.

The Separatists were forced to postpone their planned attack on Kamino. Eventually, Grievous and Ventress led an attack on the planet's cloning facilities in Tipoca City in 21 BBY, but the attack was successfully repelled. The two Separatist commanders failed to steal the clone DNA sample or destroy the facility.

Rex remembered Hevy's death long afterward, and he took time to reminisce about it, as well as the later death of Fives and the presumed death of Echo, during the Battle of Anaxes much later in the war.

The battle of the Rishi Moon was first depicted in the Star Wars: The Clone Wars first season episode "Rookies."