The entity known as the Sentinel served as the protector of a subterranean metropolis situated on the planet of Alashan; its location was a hidden underground city. This being was a consequence of an ancient complex located within the city's depths. The sheer energy output of this complex imbued the Sentinel with a detectable energy signature, potent enough to be sensed from afar, even by the sensors of an astromech droid. The creature, together with its complex, appeared to have been fashioned by an ancient civilization native to Alashan, a culture whose technological prowess and societal structure had been swallowed by time. For reasons that remain shrouded in mystery, they fortified their city with an immense metallic barrier, effectively sealing off the Sentinel and their advanced technology from the outside world.
The Sentinel was endowed with abilities and strength that bordered on the supernatural. Its arsenal included a concentrated superlaser capable of immense destruction, in addition to the power to manipulate its size and to instantly transport itself from one location to another. After Rebel archaeologists, driven by curiosity, liberated it from its [prison](/article/prison/legends], the Sentinel unleashed its wrath upon those it perceived as unwelcome trespassers. Ultimately, through the combined efforts of Rebels Luke Skywalker and Leia Organa, and Imperials Wil'm Grau and Anarine, the ancient complex suffered catastrophic damage, seemingly resulting in the demise of the seemingly indestructible creature.
Prior to the establishment of the Republic, an advanced civilization originating from the planet of Alashan engineered a power source capable of obliterating external objects at a distance of one hundred thousand kilometers from their world. Records pertaining to the origin of this power were meticulously preserved in hieroglyphic inscriptions adorning their vast underground city. To safeguard this expansive metropolis, the Alashans conceived a structure known as the control center. This complex served as the genesis of the potent energy that manifested as the Sentinel creature. Equipped with the means to defend the city and the capacity to venture beyond its confines to confront potential invaders, the Sentinel stood as a formidable guardian of the immense capital. In addition to wielding a devastating superlaser, the Sentinel could teleport to any location within the city and alter its form to either occupy an entire doorway or squeeze into confined spaces.
Upon the initial entry of the Rebels into the massive complex, they encountered an eerie silence, likening it to a subterranean tomb. The city lay buried five kilometers beneath the surface, sealed behind a massive metal gate, with the Sentinel creature confined within its boundaries, unable to escape.
Around 0 ABY, archaeologists affiliated with the Rebel Alliance arrived on Alashan, mistakenly believing it to be a lifeless planet and hoping to unearth technology that could bolster their struggle against the Galactic Empire. The whispers of the ancient Alashan civilization had persisted through the years, prompting the Rebels to investigate these rumors. Sonic scans conducted by the archaeologists revealed the existence of a colossal underground city nestled beneath the planet's barren surface. After excavating to a depth of five kilometers, the archaeologists discovered an enormous metal barrier. Driven by the prospect of untold riches, they breached the wall, unaware of the dangers that lay beyond. Subsequently, the Sentinel was released from its confinement and commenced its pursuit of the intruders who had trespassed upon Alashan. The monstrous entity systematically hunted down the entire team, leaving their dismembered remains scattered throughout the structures they had erected.
Following the failure of three consecutive routine communications, Rebel scouts were sent to the archaeological station to investigate the well-being of the Rebel team. Scouts Arlo Tyre and Wadie Firestone stumbled upon the ravaged site, discovering the slaughtered archaeologists and their habitat domes shattered from within. While Wadie analyzed his sensors, he detected an immense energy signature emanating from the main habitat dome. Arlo Tyre cautiously approached the dome, but as soon as he stood before the entrance, a concentrated burst of energy from the Sentinel creature tore through his body, killing him instantly. Witnessing the demise of his partner, Firestone hastily retreated to his Y-wing, hoping to escape the formidable force. However, as soon as he lifted his ship off the ground, the Sentinel unleashed another energy blast, obliterating the vessel and concealing his fate for the time being.
The Sentinel maintained its vigil near the city until it detected two vessels entering Alashan's atmosphere. The first was the Staraker, an experimental craft with advanced shields and speed that had been stolen from the Imperials by a team consisting of Luke Skywalker, Leia Organa, and Mici Shabandar. The second was an Imperial cruiser determined to recapture the Staraker. The Sentinel unleashed a precisely aimed blast into space, destroying the Imperial cruiser. As the Staraker desperately descended, the Sentinel fired another blast at the ship, but the experimental shields managed to deflect a portion of the energy, preventing its complete destruction. Nevertheless, the ship sustained critical damage and crashed onto the planet's surface.
Furthermore, it appeared that several Imperials had survived the destruction of their cruiser by evacuating in escape pods, and the Sentinel resolved to eliminate all of the intruders. Locating the crash site of the Rebel ship within a section of hardened lava, the Sentinel blasted away the solidified material to reach the damaged vessel. Upon entering the Staraker, the creature discovered Mici, but detecting no vital signs, it discarded her aside, leaving the ship unattended. The beast hastened back to its home, only to find that the intruders had already infiltrated the city. The Sentinel killed Eger Djambo, a stormtrooper stationed as a sentry outside the entrance, and reentered its domain. The beast promptly located another stormtrooper, Voss, and tore through his armor, hurling him from one of the city's towering structures. The Sentinel then pinpointed the main group and advanced upon them. However, concentrated blaster fire from the group triggered a collapse of the tunnel above the creature, temporarily hindering its progress.
Unfortunately for the Rebels, the Sentinel proved to be nearly invulnerable and survived the landslide. Stealthily navigating through the base, the creature attempted to ambush the intruders one by one. The Sentinel managed to sneak up on Leia Organa, but just as it prepared to pounce, Luke Skywalker intervened and pulled her from the creature's grasp. With its prey out of reach, the beast turned its attention to the Imperials Wil'm Grau and Anarine. The beast tracked them down to a tower within the city, but the Imperials were prepared for its arrival. The two men had rigged the tower with explosives, and as soon as the creature entered, the supports detonated, causing the 200 meter tower to collapse upon the beast. However, the Sentinel's power was unmatched, and it shrugged off the debris and prepared to finish off the two Imperials.
However, just as the Sentinel was about to strike, it sensed that the Rebels had located the city's main complex. Recognizing that the complex was the source of its existence and understanding the imperative to protect the structure at all costs, the beast teleported away from the two men and back to the complex. The creature also reduced its size to minimize collateral damage. Upon entering the building, the beast found Ensign Kyril Lopaki confronting Luke and Leia with a blaster pistol. The Ensign turned and fired upon the beast, hoping that its reduced size meant a reduction in power. However, the beast still retained its awesome power and swatted Lopaki aside, killing him instantly.
With Lopaki eliminated, the beast advanced on Luke and Leia. However, the young Jedi was not going to surrender without a fight, and he ignited his lightsaber. The power of the lightsaber managed to inflict damage to the creature's hand. Unfortunately for the Jedi, the Sentinel recovered from the attack and struck out at Luke, knocking him unconscious and flinging him across the room. The creature advanced on Leia next, but before it could reach her, Anarine and Wil'm Grau arrived to save the day, firing wildly into the room. Several of the blaster bolts struck consoles within the complex, staggering the creature. The intruders realized that the room was the creature's weakness, and so they began to destroy the complex. The Sentinel cried out in pain, grabbing Leia and attempting to crush her within its grip. However, at that precise moment, Luke revived and stabbed the Sentinel through the chest with his lightsaber.
The penetration of the laser sword disrupted the matrix that sustained the creature's form, creating a feedback loop within the complex. The intensity of the energy released by the creature's death triggered a massive explosion, engulfing the room in flames and forcing the intruders to flee. After several days, the group managed to dig its way out of the rubble and return to their ship. The Rebels and Imperials believed that the complex and the Sentinel had been destroyed, as the lights throughout the entire complex had extinguished following the incident.
The Sentinel was an energy-based entity, possessing a reptilian appearance. It typically assumed a massive form and reveled in toying with its adversaries. During an invasion of the city, the beast delighted in slowly stalking its prey, and as the intruders attempted to retaliate, it seemed to flaunt its invincibility by absorbing blaster fire head-on. This reaction only changed when the creature faced Luke Skywalker and his lightsaber, which caused it pain. In this instance, the beast adopted a defensive posture, lashing out erratically.
The creature also exhibited a clear enjoyment of murder and mayhem. It was known to laugh appreciatively while killing, and it carried out its killings in a gruesome manner, dismembering the victim's body. Additionally, when the beast first searched the Staraker, it left behind a scene of devastation within the ship. This same destruction was evident when the Sentinel first attacked the archaeologists, as it tore apart their habitat domes from within, seemingly driven by its own destructive impulses.
The Sentinel possessed extraordinary powers granted to it by the Forever control center. It possessed immense strength, capable of easily tearing through stormtrooper armor with its bare claws. Furthermore, the beast had the ability to teleport from one location to another, as demonstrated when it sensed that the complex was in danger and transported itself back to its source of power. Finally, the Sentinel demonstrated the ability to alter its size when it entered the complex, shrinking its form to minimize damage to the delicate structure.
The Sentinel, although initially unnamed, made its debut in the "World of Fire!" storyline featured in the comic book series Star Wars Weekly, specifically in Star Wars Weekly 107 published on March 12, 1980. It was later identified as such in "The Guardian of Forever!" storyline published in Star Wars Weekly 113 on March 12, 1980. Both comics were authored by Chris Claremont and illustrated by Carmine Infantino and Gene Day.
A similar creature known as the "Night Beast," appeared in The Night Beast, a comic strip story arc written by Archie Goodwin, illustrated by Al Williamson and published in 1982. Goodwin served as an editor on both the "World of Fire!" and "The Guardian of Forever!" storylines.