HK-55

In the year 3631 BBY, HK-55 aided his masters, Lana Beniko and Koth Vortena, in their mission to rescue the Commander from Arcann's carbonite imprisonment on Zakuul. While Lana and T7-O1 infiltrated the prison, HK remained with Koth in their getaway shuttle. However, their escape was detected, leading to Zakuulan forces shooting down their shuttle. The pair fought off Eternal Empire troopers and managed to get the shuttle airborne once more, arriving just in time to save Lana and the Outlander from Vaylin. HK-55 provided direct assistance to the Outlander, preventing them from falling off the boarding ramp.

Regrettably, the damage inflicted by Vaylin caused the group's shuttle to crash in the Endless Swamp. After surviving the crash, HK-55 informed his masters of a large technological object he had detected in the swamp. While the others remained behind to conceal evidence of the crash, HK-55 accompanied the Outlander in exploring the swamp, eventually locating the object, which turned out to be a derelict frigate. Upon Koth and Lana's arrival, HK-55 informed them that the starship's architecture was unlike any Zakuulan design, whether ancient or modern. Koth identified the ship as the Gravestone, the legendary vessel that had single-handedly triumphed against the Eternal Fleet. The very existence of the Gravestone convinced Koth that victory against Arcann was within reach.

Following the elimination of the creatures inhabiting the Gravestone, HK-55 began patrolling the area while his masters gathered necessary parts and supplies, eliminating any skytrooper scouts he encountered. Later, upon returning to the Gravestone to resume his guard duties, HK-55 noticed an iknayid that somehow evaded his shots. He pursued the creature relentlessly, eventually encountering a whole pack of iknayids, which he promptly dealt with.

As soon as the Gravestone was repaired, the Eternal Empire launched an attack. During the battle, Senya Tirall, a defector from the Knights of Zakuul, joined the party. Koth was hesitant to trust her due to her past as a Knight who had hunted him down for desertion. HK-55 reminded his masters that enemy reinforcements were approaching, prompting Koth to postpone the argument as they managed to launch the Gravestone. The Eternal Fleet arrived to intercept them and opened fire. HK-55 fought alongside the Outlander against skytrooper boarding parties as they made their way to the gunner station. By firing the omnicannon, they managed to destroy over two dozen Eternal Fleet warships before escaping into hyperspace.

Unfortunately, the use of the omnicannon caused the hyperdrive to malfunction, resulting in the Gravestone dropping out of hyperspace in an unknown location. While awaiting repairs, HK-55 secretly monitored everyone's activities while exploring the ship. He later encountered the Outlander and inquired if the "meatbag bickering" had finally ceased. HK-55 then mentioned that several sections of the Gravestone were sealed off before adding that while examining a mysterious monolith to determine if it could be weaponize, he was interrupted by Senya.

Upon arriving at the shadowport known as Asylum and meeting with Koth's crew, Koth tasked the Outlander with finding his engineer, Tora. HK-55 accompanied the Outlander due to having Tora's image in his databanks. After battling their way through the Starbolts gang, they located Tora in a precarious situation with another gang leader named Tanno Vik. When Vik declared his intention to punish Tora for insulting him and his mother, HK-55 threatened to disarm him.

After the Outlander resolved the situation, they proceeded to meet with Senya, who intended to introduce the Outlander to potential allies. She then opened a concealed door, but before HK-55 could enter, he was struck by an electromagnetic pulse that incapacitated him and erased his memory. Upon regaining consciousness, HK-55 began wandering Asylum before Lana found him and brought him back to the Gravestone. Koth immediately suspected Senya of betrayal, but Lana believed that Senya's contacts posed the real danger and asked HK-55 where he had last woken up.

Gathering the crew, HK-55 guided them to the concealed entrance. Storming the sanctuary, they found the Outlander in a standoff with the Scions of Zakuul. The Scion leader, Heskal, revealed that the reason they could not foresee the Outlander's future was that Emperor Valkorion had survived within the Outlander's mind. HK-55 promptly scanned the Outlander's brain but found no evidence to support the presence of another mind.

Senya soon delivered another revelation, identifying herself as the mother of Arcann and Vaylin. The Outlander's party then returned to the Gravestone, where Koth confronted Senya for her deception. HK-55 interrupted his tirade, announcing that T7 had relayed a message from the Lady of Sorrow, a mysterious information broker operating on Zakuul, who wished to communicate with the Gravestone's computers. HK-55 remained behind to eliminate the remaining alien creatures aboard the ship while the Outlander and Senya traveled to Zakuul to recruit the Lady of Sorrow.

The Lady of Sorrow was later revealed to be an advanced droid named SCORPIO. Upon the Outlander's return to Asylum, SCORPIO requested full access to the mainframe, but was instead assigned to the hyperdrive. When HK-55 threatened SCORPIO, she insulted his lack of intelligence.

Shortly after the Outlander was summoned to the Scions' hideout by Heskal, Asylum was attacked by Arcann's forces. During the fighting, Arcann's forces seized control of the control spar, which powered the docking clamps holding the Gravestone, preventing their escape. HK-55 fought to rendezvous with Koth before holding off the enemy as the Outlander proceeded to the control spar to release the Gravestone. HK-55 subsequently joined his master as the Outlander was confronted by Arcann. After a prolonged and difficult battle, Arcann was about to unleash a blast of Force energy to kill the Outlander, forcing HK-55 to step in between Arcann and his master. This action saved the Outlander but caused HK-55 to sustain severe damage and shut down.

The damage inflicted by Arcann's attack was initially considered irreparable, but Dr. Juvard Illip Oggurobb, the chief scientist of the newly formed Alliance fighting against Zakuul, managed to rebuild HK-55 at his laboratory on Odessen, albeit with some modifications to his chassis. However, HK-55's memory core was unrecoverable, resulting in his programming being restored to factory settings and the complete loss of any memories prior to his reactivation. Dr. Oggurobb requested the Outlander's assistance in making the final calibrations to HK-55's security and assassination programming. The Outlander initially found HK-55 in the research lab, blasting every droid in the room to scrap while the terrified lab technicians fled from his line of fire, having opened fire before his test was ready to secure a tactical advantage. With the Outlander's help, HK-55 conducted a series of scenarios to refine his targeting subroutines to the Outlander's satisfaction.

At one point, HK-55 found himself in an unfamiliar location, restrained to an interrogation table. He was greeted by an enthusiastic droid named Z0-0M, who released him at his request. Subsequently, a hologram of his captor appeared, revealing himself to be the terrorist known as the Shroud. The Shroud revealed that he had copied HK's memory core to gain access to Odessen base, where he planned to plant bombs to destroy it and the Outlander. The Shroud then signed off, summoning battle droids and mercenaries to subdue HK. Zeeyo chose to defend HK, considering him her friend, and discovered that her chassis contained an impressive array of weapons. As they fought their way through the Shroud's base, the Coil, HK and Zeeyo uncovered the Shroud's holorecordings, which detailed his unwavering hatred for the Outlander for thwarting his plans of galactic conquest; a museum of droid heads the Shroud had replicated, including a copy of HK-47's head; and a captive Exarch named Malforia. Throughout their journey, Zeeyo began experiencing periodic reboots that regularly erased her memory, which HK theorized was caused by an electrical surge. Furthermore, during their confrontation with Malforia, Zeeyo discovered that she was a replicator droid, capable of changing her appearance to resemble anyone she had recently encountered.

After ascending from the underwater section of the Coil to the asteroid in space connected by a skyhook and reaching the hangar, HK and Zeeyo encountered another HK-55. This HK unit's design was copied from the original HK-55 as he appeared before the Battle of Asylum, lacking the battlescars and customized repairs the original HK-55 had received since. The duplicate HK-55 declared Zeeyo to be the Shroud's property, showing them a holorecording of Zeeyo talking to the Shroud, revealing that she was responsible for capturing HK and planned to wipe his memory with an electrical surge, only to be accidentally affected herself. HK-55 and Zeeyo then fought against his duplicate. However, upon critically damaging the replica HK-55, the base began to initiate its self-destruct sequence, and the computer requested the deactivation code. Zeeyo pleaded with the duplicate HK-55 to stop the self-destruct, but he simply replied that the computer wasn't talking to him before expiring. With time running out, HK-55 and Zeeyo defended their escape ship from the mercenaries attempting to seize it, before escaping the base's destruction.

Upon returning to Odessen and confronting the Shroud, the droids were surprised to see the Human acting nervously, claiming that Zeeyo was the true Shroud. He explained that he was the fifty-first person to undergo surgery to resemble her Human male guise, and was coached using the very holorecordings the droids discovered at the Coil, as the true Shroud never put herself at risk. No longer wanting to destroy the Alliance base, Zeeyo stepped up to her subordinate and demanded that he stop the self-destruct sequence. The bomb computer then recognized her as the true Shroud and deactivated all the bombs. After HK dealt with the imposter, he spoke with Z0-0M about her future just before Lana Beniko, Theron Shan, and the Commander themselves arrived to find two unknown individuals with HK-55 in their War Room. He expressed fatigue and promised to explain the situation.

HK-55 appears as a companion character within the digital expansion titled Knights of the Fallen Empire for the Star Wars: The Old Republic video game. Kristoffer Tabori provides his voice in the game, having also voiced HK-47, HK-50, and HK-51.

HK-55 marks the first instance of an HK model whose primary function is not assassination, but rather bodyguarding. HK-55 is also the second HK unit to refer to organic beings as "meatbags," following HK-47. The HK-50s and HK-51s typically referred to them simply as "organics," with the HK-51 referring to its targets as "undesirables" or "troublemakers."

Despite HK-55's apparent demise in Chapter VIII: Taking Flight, players were presented with a limited-time offer to reclaim him as a permanent companion. Players who maintained a subscription to Star Wars: The Old Republic by January 11, 2016, were granted the in-game mission titled "Arma Rasa", where they encountered the rebuilt HK-55. Furthermore, players who were subscribed to the game between January 11, 2016, and August 1, 2016, received a bonus chapter of story content known as "Shroud of Memory." This chapter allowed players to assume the role of HK-55, gaining access to the character's unique abilities and dialogue options. Players who did not have an active subscription during the specified dates were required to purchase it from the Cartel Market.

In Chapter IV: The Gravestone, players engage in conversation with HK in the Endless Swamp on Zakuul. During this interaction, players have the opportunity to reprogram HK to follow their commands, regardless of the potential consequences for other characters. If the reprogramming is successful, players can later instruct HK to eliminate a group of defenseless Zakuulan exiles.

In the mission "Arma Rasa", players reunite with a reconstructed HK-55. Throughout the mission, HK presents a series of scenarios involving potential targets, allowing players to authorize or prohibit HK from eliminating specific individuals.

In the Bonus Chapter: Shroud of Memory, players assume control of HK-55. The mission generally offers three distinct dialogue options for portraying HK: kind, humorous, or cruel. Upon encountering the janitor Jollo, HK can choose to kill or imprison the Twi'lek. Later, during the meeting with Exarch Malforia, HK can either kill her immediately or release her, in which case she fights alongside you until her death in the vacuum of space. At the conclusion of the Chapter, HK can decide whether to destroy Z0-0M as a threat or offer her a place in the Alliance.