Zo Resken

Zo Resken, formerly known by his title Prophet of Clarity, is a San'Shyuum who once served the Covenant as the Secondary Administrator to the High Prophet of Truth. Some time during his career, he wrote a document titled Notes on the History of the Covenant. A descendant of Mken 'Scre'ah'ben, the Prophet of Inner Conviction in the Covenant's early years, Resken abandoned the Covenant in its final days during the Great Schism and allied himself with the Sangheili. He would eventually find and settle on the lost Ussan colony of the Refuge.

Early career
Zo Resken was born a descendant of Mken 'Scre'ah'ben, the Prophet of Inner Conviction in the early years of the Covenant. Resken began his career in the Covenant as a communications officer, and during this time he acquired numerous technological skills, many of which he would continue to employ long after leaving the post. At some point prior to the Human-Covenant War, Resken encountered the future High Prophet of Regret while the latter was the Vice Minister of Tranquility, and he had treated Resken well. Resken, unlike most of his kind, enjoyed the company of the Sangheili outside of his work, and would befriend many of them, notably Field Commander G'torik 'Klemmee and his uncle, High Councilor Torg 'Gransamee, of whom Resken believed was in fact G'torik's father. He also served within the Palace of the Hierarchs as a buffer between the High Prophet of Truth and the Prophet of Stewardship, prior to the latter being given control of the Fleet of Particular Justice's military assets. Zo Resken had been present in the Fleet of Particular Justice when it had arrived in the Soell System in September, 2552, after pursuing the from Reach. Resken suspected that the Prophet of Truth wanted him to serve as a buffer between the Hierarch and the Sangheili within the fleet, due to his affinity with the species. During the battle on the surface of the newly-discovered Installation 04, Resken oversaw Sangheili combat units that fought against the human forces. Towards the end of the battle, Resken only just managed to withdraw his troops from the ring before it was destroyed by Spartan John-117. At some point following the destruction of Installation 04, Resken wrote a secret document, the Notes on the History of the Covenant, in which he briefly recounted the history of the Covenant, the integration of its multiple client species, as well as his own personal opinions including his distrust of the Jiralhanae and private disagreements regarding the Hierarch's genocidal campaign on the human race. Knowing that the opinions detailed in the document would be considered heretical by the Covenant, Resken kept it hidden safely locked away, only to be revealed to the public after his death. Resken wrote the original document in the San'Shyuum language. Shortly after the Halo ring's destruction, Resken found himself appointed as the Secondary Administrator to the Prophet of Truth on High Charity, a position in which he was secretly embittered with. The discovery of a second ring less than two months later led to newfound elation within Resken, who had been despondent after the destruction of Installation 04. This happiness would be short-lived, however; moments after High Charity had arrived at the installation, Resken received news of the Prophet of Regret's assassination at the hands of the same "Demon" that had destroyed Alpha Halo.

Installation 05
Shortly after Regret's death, Resken met with G'torik 'Klemmee and Torg 'Gransamee in one of High Charity's Hanging Gardens. While listening for potential eavesdroppers, the three discussed recent events. Resken considered the possibility that the loss of Installation 04 was perhaps indicative of the fact that the Covenant was unfit to undertake the Great Journey at that time due to a lack of spiritual unworthiness, citing an event during the early days of the Covenant where they had lost a unique Luminary that may have propelled the Covenant on its path and its loss had been similarly mourned. When Torg blamed the loss of the Halo ring on a military failure, and G'torik subtly reminded him to be cautious of how he spoke to the Prophet, Resken told them to speak freely with him, as he sought to strengthen his allegiance with the Sangheili. While viewing sensor footage of the debris field of Installation 04, as well as the newfound Installation 05, the three conversed about Regret's assassination. While Resken had great respect for the Prophet of Regret, he could not help but be angry about his reckless attack on the previously-unknown human homeworld. G'torik informed Resken that a massive force of Phantoms had been sent to protect Regret, but had been withdrawn before reaching him, seemingly on the orders of the High Prophet of Truth. While the three speculated on the reasons Truth had pulled the Phantoms back, Resken was summoned to the Palace of the Hierarchs by the Prophet of Truth. Before leaving, Resken told the two Sangheili that he would try to tell them of anything he learned.

Resken had installed a share-input directive into the Prophet of Truth's chair that morning, using his knowledge from his previous position as a communications officer, and his own resentment of his job post and a desire to advance his own agenda. While waiting for the Chieftain of the Jiralhanae, Tartarus, to arrive, Resken was approached by Truth. The Prophet ensured that Resken had not told any within the Covenant of his secret meetings with Tartarus, including his fellow Hierarch, the Prophet of Mercy, before informing Resken that the Prophet of Exquisite Devotion would be joining them, a San'Shyuum that Resken truly disliked. Making sure that refreshments were on hand for the visitors, Truth subtly warned Resken to treat Exquisite Devotion with the utmost respect, as Resken was to be transferred to Exquisite Devotion's authority. Exquisite Devotion was to oversee High Charity's governance as the Hierarchs, along with the High Council, would be leaving to commence the Great Journey following the discovery of the Ark. After Truth withdrew into the reception chamber, Resken briefly considered what he saw as a demotion before Tartarus and Exquisite Devotion arrived. As Resken served the two visitors with their refreshments, Truth arrived and promptly dismissed Resken from the room. After briefly considering whether he should switch the listening device on, due to the disastrous consequences should it be discovered, Resken decided to activate it. While eavesdropping, Resken heard the trio discussing the impending replacement of the Sangheili Honor Guard with the Jiralhanae, as well as the replacement of the Sangheili with Jiralhanae in the fleets over Earth. Resken was shaken by what he had heard, as well as the uncertainty about whether his device had been discovered.

Some time after this meeting, Resken reported to Exquisite Devotion in the latter's office. Immediately, Exquisite ordered Resken to stand in his presence, permitting him use of his anti-gravity belt. Exquisite Devotion told Resken that he would be accompanying him to a meeting with the High Council the following day as his assistant, before confirming what Resken had overheard previously; the Covenant Honor Guard's Sangheili would be replaced by the Jiralhanae. Exquisite Devotion cited the former Supreme Commander of the Fleet of Particular Justice's failure to protect Alpha Halo, as well as the Sangheili Honor Guard's failure to prevent the Prophet of Regret's death as the main motivators behind the switch, as well as wavering allegiance to the Covenant in the Hierarch's eyes. Furthermore, the Jiralhanae were to be promoted above the Sangheili. Perturbed, Resken addressed the possibility of a Sangheili rebellion as a result, an outcome that Exquisite Devotion disagreed with. Resken was ordered to use a nearby comptroller to send several items to Exquisite Devotion that the latter had ordered. While he carried out his task, Resken resolved to deliver a warning to his Sangheili compatriots, suspecting what was to come.

Later that day, Zo Resken met with G'torik 'Klemmee within the Chancel of Recovery. As it was frowned upon for Sangheili to be seen within a healing facility, G'torik was there under the pretence that he was checking on the San'Shyuum's well-being. Here, Resken disclosed all that he had learned: the upcoming replacing of the Covenant Honor Guard, the orders sent by the Prophet of Truth to Jiralhanae forces already stationed at Earth and the High Prophet's sending of his own fleet to the planet, and the large order of traditional Jiralhanae weaponry that Truth had placed with the Sacred Promissory. Resken warned G'torik that Truth might be preparing to ambush and quickly wipe out the Sangheili with the newly-equipped Jiralhanae-led Covenant military. G'torik then confirmed Resken's suspicions that Truth had pulled the Phantoms back and had allowed Regret to die, having heard word from his uncle who had conversed with one of the Phantom's pilots. Resken told G'torik to only warn those Sangheili of significantly high rank who could keep quiet and so preserve their advantage of surprise if the Hierarchs discovered what they had learned. Resken also warned the field commander that the Flood had been released from quarantine on the surface of Delta Halo, and that the Prophet of Truth may use the parasite to his advantage while he replaced the Sangheili in the Covenant. When questioned by G'torik on his own motivations for warning the Sangheili, Resken considered the many reasons that he had not yet thought to question: an influence over the Sangheili should they emerge victorious in a Covenant civil war; a deep-seated revulsion for the Prophet of Truth and Tartarus and a personal waning of faith in the Covenant as a whole, considering the Hierarch's scheming in the presence of a Halo ring. He settled on telling G'torik that he knew that the San'Shyuum would not survive without the Sangheili, and the two species would need to be unified if they were to survive the Flood and the humans.

Great Schism
The following day, while walking through one of High Charity's Hanging Gardens without aid from his anti-gravity belt or chair following his ancestor Mken 'Scre'ah'ben's example, Resken heard the Prophet of Truth's denouncement of the Sangheili over the city's broadcast system. Knowing that civil war had indeed broken out within the Covenant, Resken made for the exit but was stopped by a Jiralhanae captain and a Mgalekgolo pair. The Jiralhanae told Resken that the Prophet of Exquisite Devotion had sent for him, and warned him that the Mgalekgolo would forcibly take him if he didn't comply willingly. Resken was allowed to retrieve his anti-gravity chair before being escorted to the Gravitational Refinement chamber in the Trial Court for Tools of Conquest. Upon arrival, Exquisite Devotion had his Jiralhanae disable the weaponry in Resken's chair. Exquisite Devotion revealed to Resken that he had captured. To his horror, Resken recognised all three of them: High Councilors Duru 'Scoahamee and K'hurk 'Bornisamee, as well as K'hurk's nephew Tilik. Exquisite Devotion told Resken of the massacre of the Sangheili Councilors and their guardsmen at Installation 05's control room, gleefully stating that Torg 'Gransamee and G'torik 'Klemmee had been part of the slaughtered group, before demonstrating his control over the rooms artificial gravity, slamming Duru onto his back. Devotion exclaimed that he would use the room for interrogation. Resken was forced to watch in terror as Exquisite Devotion crushed the Sangheili's hand. Exquisite Devotion revealed that he had, with the aid of several spy drones, overheard his conversations with Torg'Gransamee and 'Klemmee in the Hanging Gardens, and had in fact deliberately imparted information about the Sangheili the previous day, knowing that Resken would go on to tell 'Klemmee and the drones had confirmed the fact. Exquisite Devotion then revealed to Resken that the disgraced former Supreme Commander of the Fleet of Particular Justice, Thel 'Vadamee, made Arbiter of the Covenant after his failure at Alpha Halo and who had been thought to have been killed by the Flood inside Delta Halo's Library, had somehow survived and was leading an uprising of Sangheili against the Jiralhanae on the surface of the installation. Exquisite then ordered Resken to impart information regarding the Arbiter and his forces, as well as the missing G'torik 'Klemmee's whereabouts. Resken truthfully told him that he did not have any knowledge of Exquisite Devotion's demands. Unbelieving, Exquisite continued to torture Duru 'Scoahamee in front of Resken, slowly crushing the Sangheili's body from the knees upward until his whole body was destroyed and mangled beyond recognition. Resken was utterly sickened by what he saw but was forced to watch until Duru breathed his last. Exquisite Devotion then ordered Melchus, Tartarus' second in command and the leader of the massacre of the Sangheili Councilors, to bring Tilik 'Bornisamee forward next. Exquisite then turned to Resken, telling him that only if he carried out the gruesome killing would he be allowed to live; should he refuse, Resken would be killed in the same manner. Resken briefly considered complying, if only to prevent Exquisite Devotion from taking even longer to kill him. Ultimately he could not bring himself to do it, resigning himself to his fate. Exquisite then ordered a pair of Jiralhanae to hold Resken while he finished killing the two Sangheili in the chamber.

While Resken was being escorted by the Jiralhanae toward the rear entry of the chamber, he considered his options. Knowing that he could not use physical strength or his damaged anti-gravity chair to escape. Resken contemplated using the records hidden within his chair to bargain with Exquisite Devotion, as he had learned that the Refuge, a Forerunner shield world and holdout of a Sangheili rebellion in the early days of the Covenant that was thought to have been destroyed by the rebels in an apparent mass-suicide in order to evade the Covenant, had possibly survived. He considered using this information to perhaps have Exquisite spare his life. As he began to realise that the information would be forcibly taken and he would be killed regardless, a group of Sangheili led by G'torik 'Klemmee, of whom Resken had believed dead, ambushed the party, swiftly killing the two Jiralhanae escorting Resken. G'torik revealed that he had survived by being knocked off the balcony, and had stowed away on a Phantom returning to High Charity. Resken knew one of the Sangheili with G'torik, a commander named Crun 'Brinsmee and was introduced to the other, an engineering officer known as Tul 'Imjanamee. Resken was forced to leave his anti-gravity chair behind as he would be unable to fit it through the complex network of pipes and energy conduits the group needed to pass through. Tul revealed that they were headed for a maintenance vessel that would allow the group to leave High Charity. Suddenly, a pair of Mgalekgolo arrived in the room. Resken told the Sangheili to go ahead while he distracted the Hunters, to which G'torik refused, telling him that they had specifically come to rescue the San'Shyuum. Exquisite Devotion appeared, ordering the Mgalekgolo to hold their fire while he addressed the rescue party. Exquisite told them to hand over Zo Resken, and he would let the others survive, to which G'torik refused. Exquisite then ordered his Mgalekgolo to open fire. The first volley of assault cannon fire struck near Resken, knocking him over and burning the right side of the San'Shyuum's face. 'G'torik and Crun opened fire on several transmutation cubes near their attackers with their plasma rifles, detonating them. The resulting explosion obliterated the Mgalekgolo pair and knocked Exquisite Devotion out of his chair. G'torik immediately made for the downed Prophet, and he killed the cruel San'Shyuum by cutting him into three parts with his energy sword. With the resulting chain-reaction threatening to consume the room, the group made for the exit, encountering the Huragok Sluggish Drifter. With the aid of the Huragok, the group made their way into a hangar bay, entering a small maintenance shuttle. As the vessel made its way out into the city proper, Resken witnessed the mayhem as the Great Schism consumed the planetoid, as well as the departure of the Prophet of Truth on board the Forerunner Dreadnought. The group watched in horror as the entire city was plunged into darkness as it's main source of power was severed, the final remaining Hierarch leaving to lead his remaining fleets to Earth, to seek out the Ark. Resken wondered aloud as to why he was leaving Delta Halo, to which G'torik replied that Tartarus was taking the Sacred Icon to the control room. The Sangheili went on to say that the Arbiter was planning to stop him, as they had learned the truth of the nature of the Halo Array. He also reported that the Flood were rumored to be present as well. As the vessel left High Charity's dome, it rendezvoused with the supply vessel Journey's Sustenance, captained by Dero 'S'budee and the ship swiftly transitioned into slipspace, leaving the devastated holy city of the Covenant behind.

Sometime later, the Journey's Sustenance arrived in the Ussan system, a star system marked as forbidden by the Covenant, and so considered by D'ero to be safe. Upon arrival, the group shed all their Covenant titles and honorifics, signifying their split from the empire. As the group considered their next move, Resken wondered about what would happen to the Sangheili on the vessel as most of them had only ever known the Covenant, and wondered if those still on their homeworld of Sanghelios would even believe the treachery committed by the San'Shyuum against their own people. While the group sought guidance from Resken, he told them that he was no longer a Prophet, having shed the title due to his abandonment of the Covenant. He expressed sorrow that he had been unable to speak with the Arbiter before departing from the Coelest system, to which Tul 'Imjanam replied that he had received notice from Commander Rtas 'Vadum that he and the Arbiter had succeeded in stopping Tartarus at Delta Halo's control room, but the battle at the installation was ongoing. Remorsefully, Resken told the group that the schism was the 'third vector of chaos' theorized by his ancestor Mken 'Scre'ah'ben in his writings. The first and second vectors had proven to be the humans and the Flood, and the third and final was the civil war - the death knell of the Covenant. As D'ero angrily declared that all who had aligned with the Prophet of Truth and the Jiralhanae should be destroyed, Resken swiftly changed the subject, asking the Sangheili what he knew of the system they found themselves in. When D'ero mentioned the name of the system, Resken immediately recognised the name from Mken's writings. He expressed a desire to explore the system, to perhaps find surviving descendants from the Sangheili rebels who had been thought destroyed by the Covenant. While Tul considered that the group return to Installation 05 to aid the Arbiter, Resken responded that they must remain, as they would not be able to win every fight, a lesson that the ancient rebel leader, Ussa 'Xellus had learned.

The Refuge
By early 2553, the vessel was still searching the Ussan system. Zo Resken determined that they stay their course, despite knowing that the odds of discovering anything was extremely remote. The crew was becoming frustrated; as their food supply dwindled, the group began to argue over insignificant matters. The Journey's Sustenance, a small supply ship, was not equipped with long-range scanning equipment, forcing them to painstakingly search the entire system to look for any signs of the long-forgotten society that had once resided there. Most of the crew aside from Resken wished to give up the search, having discovered little more than scattered pieces of artificial rubble bearing Forerunner ideograms in over half a solar cycle.

One day, as Resken was studying the latest collection of relics the Journey's Sustenance had collected from the system, G'torik arrived and informed him that Tul had decoded a set of subspace communications, revealing that the Covenant had been brought to an end, as well as the death of the Prophet of Mercy, the fall of High Charity to the Flood and its subsequent destruction, the deactivation of the Halo Array at the Ark by the "demon" and the Prophet of Truth's death at the hand of Arbiter Thel 'Vadam. G'torik also confirmed the alliance of the Sangheili with the humans at the close of the war and the true nature of the Halo Array. Resken mused that his ancestor's prophecy had proven correct in its prediction of the Covenant's end, as well as the similarities between the end of the Forerunners and the Ussans. G'torik told Resken that he had learned of the Arbiter's return to Sanghelios, and his efforts to unite the various keeps to his cause. Resken felt some inward jealousy toward his friend, knowing that he and the others could return to their homeworld while he himself had no world to return to. Resken was completely shaken by the knowledge that he might well be one of the few remaining San'Shyuum left in a galaxy where many now hated them, and had no safe place to return to, following the destruction of High Charity. Refusing to give up his search of the Ussan system, Resken reminded G'torik of logs discovered from others who had spoken to Kig-Yar pirates that reported discovering larger artifacts in the system, with one claiming to have been fired upon by something within the asteroid belt. Despite this, Resken resolved to agree with the rest of the group should they decide to depart for Sanghelios, noting that he didn't have any real authority over them. Suddenly, D'ero summoned Resken, claiming to have found something the San'Shyuum would want to see. Upon arriving at the bridge, D'ero magnified the ships sensors, revealing a previously-undetected artificial object larger in size than the Journey's Sustenance - in truth a part of the disassembled Shield World 0673.

As the supply ship slowly approached the Refuge, they learned of an ongoing battle there. They then detected a tiny maintenance vessel spiralling through space, its engines previously having been damaged by rebel forces of the Refuge. Resken offered to guide D'ero as the Sangheili made to bring it into the supply ship's freight hold. Upon the successful interception of the small vessel, Resken, along with G'torik and Tul armed themselves with carbines and made for the freight bay. Resken called to any survivors. As he reached the hatch to the maintenance vessel, a Sangheili emerged. The Sangheili spoke in a dialect that somewhat differed from the Old Sangheili language. After learning that the stranger thought that Resken was one of the gods, Resken told Tul to tell the stranger that he was simply a friend of the Sangheili and that he meant no harm. D'ero warned Resken and the others to vacate the freight bay, as the maintenance vessel the strange Sangheili had arrived in was unstable and liable to explode, necessitating the decompression of the bay. The group made it out before D'ero vented the freight bay, propelling the maintenance vessel into space where it exploded. After verifying that the Journey's Sustenance was undamaged, Resken disregarded the suggestion from D'ero that the vessel could have been a trap and instructed them to use translator devices to communicate with the stranger. The Sangheili introduced himself as V'ornik 'Gred and confirmed that the party had indeed discovered the Refuge. Resken was overcome with the desire to make proper contact with the colony, to which D'ero acquiesced, permitting G'torik and Tul to accompany the San'Shyuum. When Sluggish Drifter entered, Resken told V'ornik that the Huragok could repair anything in their colony. Overjoyed, V'ornik gladly allowed the group to accompany him.

Shortly after arriving on the Refuge, V'ornik contacted Xelq 'Tylk, the acting commander of the Refuge while the kaidon, Bal'Tol 'Xellus was engaged in a floatfight match with the leader of the rebellion, a Sangheili going by the name of 'Kinsa. Xelq permitted the group entry, allowing Sluggish Drifter to repair the long-deactivated monitor of the shield world, Enduring Bias. The monitor proceeded to save Bal'Tol from death at the hands of V'urm 'Kerdeck before killing 'Kinsa when the rebel leader attempted to destroy Enduring Bias with his mec-missiler. Zo Resken later accompanied Enduring Bias, Sluggish Drifter, Xelq, G'torik, Tul and a group of eight patrollers on a section-to-section shuttle headed for Section Five of the Refuge, where the remaining rebels were located. While both Resken and Xelq considered if Enduring Bias would be able to deactivate the repellent field over the airlock into Section Five, the monitor assured them that he could, easily bypassing the field. Resken warned Xelq that there could still be rebel holdouts that would not yield the territory they had gained. As they entered the section, Resken was overcome with joy at having discovered the very colony that his ancestor Mken 'Scre'ah'ben had encountered during the earliest days of the Covenant. He was fascinated with both the Forerunner technology as well as the Ussan innovations to the pre-existing designs. After leaving the vessel in the hangar, Resken and the rest of the heavily-armed team made their way into Section Five. As Enduring Bias burned down rebel mec-missiler bolts with his laser weapon, the two patrollers armed with rocket launchers killed the attackers. Resken ensured that Enduring Bias was recording everything that was happening; the San'Shyuum knew that the group was making history, and wished for the rest of the colony to witness the downfall of the 'Greftus Faction. Eventually the group entered the Hall of the Godminds's scripture garden. Resken was immediately hit by the foul smell of unwashed clothing and raw sewage. He was somewhat saddened to see some of the sculptures had been knocked down. Upon discovering the desecrated sculpted busts of the Refuge's founders, Ussa 'Xellus and his spouse Sooln, Resken surmised that the busts had been vandalized due to their clan ties with Bal'Tol. As the group attempted to enter the main Hall of the Godmind building, they were immediately assailed by weaponsfire from rebels entrenched within. As the rocket-launcher equipped patrollers returned fire, Enduring Bias ordered them to cease fire, as they would damage the machinery. Instead, the monitor entered the building himself, using his repellent field to absorb enemy fire while surgically neutralizing threats with his laser beam. Most of the rebels surrendered, while those that refused were killed. The group then prepared to move on to the damaged protein synthesizer that was the source of the Blood Sickness illness that plagued the colony.

Some time later, after the group had cleared the remaining rebels who had refused to surrender out of the various sections of the Refuge, Resken gathered with the rest of the crew of the Journey's Sustenance. They, along with the entirely of the colony, had gathered to watch as Bal'Tol delivered a speech to its inhabitants. The kaidon announced the dissolution of the Covenant and his intention to reunite the colony with Sanghelios. He offered his people the freedom to choose if they wished to return to their species' homeworld or remain on the Refuge, which he promised was to become a safer colony to live in. Bal'Tol announced that Enduring Bias and Sluggish Drifter had repaired the malfunctioning protein synthesizer and a cure for the Blood Sick had been formulated and was being distributed to the afflicted. As Bal'Tol initiated the assembly process for the long-disassembled Refuge, G'torik asked Resken what he planned to do afterwards. Resken replied that he wished to remain on the Refuge, expressing a desire to study the Forerunner history behind the colony, and the San'Shyuum had no real place to go after the fall of High Charity. Bal'Tol accepted this without protest, on account of Resken bringing forth the source of the colony's salvation. Resken then watched as the long-awaited reassembly of the colony occurred; long-separated sections reconnecting into place. Resken was struck at how the newly-assembled Refuge resembled a smaller Halo ring.

Personality and traits
Unlike most San'Shyuum, Zo Resken enjoyed the company of Sangheili outside of his work and managed to befriend some of them, similar to the High Prophet of Regret in this regard. He also had a sense of honor, and was unwilling to torture Sangheili prisoners, preferring to die instead. Unlike many members of his species, Resken's title was not ironic: prior to the Great Schism, he had began to see the numerous faults in both the Covenant religion and it's leading members. He realised that if the Prophet of Truth would carry out his schemes to replace the Sangheili, one of the core founding species of the Covenant, and incite civil war in the very presence of a Halo ring, itself central to the Covenant's religion, then other parts of the Covenant's origin might be false.

Resken was also very determined, scouring the Ussan system for the Refuge for much of a solar cycle after the fall of High Charity, even as the rest of his crew grew weary from the search. At his heart, Resken was a true historian, expressing wonder at the Forerunner designs of the Refuge as well as the additional Ussan innovations to the existing Forerunner technology. This was ultimately his primary reason for remaining on the Refuge after its reassembly process had been completed, wishing to commit the rest of his lifetime to studying the vast array of Forerunner history on the shield world.

List of appearances

 * Halo: Broken Circle