Lithos

The Gateway, a Lithos situated on Genesis.

The Lithos is a term designated by human researchers to refer to a series of Forerunner access nodes situated across the Milky Way galaxy, designed to allow for access to the Domain. They are present on numerous worlds and megastructures both natural and artificial.

Overview

The Lithos on Boundary.

Lithos sites serve as nodes that provide access to the Domain. During the era of the Forerunner Ecumene, they could be used to provide unlimited access to the vast knowledge reserves of the Forerunners.

After the New Phoenix Incident in 2557, the artificial intelligence Cortana was able to infiltrate and take over the Domain from the Gateway site located on Genesis. After this, access to the domain became impossible except by way of an individual with an identical neural pattern to Cortana, such as a clone of Cortana's original brain donor Catherine Halsey. The clone could be used as a "key" to allow access to the domain. Dovo Nesto believed that accessing the domain via a Lithos required the sacrifice of one's body - something he was prepared to do in order to become effectively an immortal god.

It is unclear how, or if, the Forerunners distinguish regular Lithos nodes and "gateways" like the one featured on Genesis. Under Project BOOKWORM, the United Nations Space Command keeps an eye on several such potential sites, they remain largely in the dark about the finer differences between them.

Worlds containing Lithos sites

Lithos sites are present across a number of worlds previously inhabited by the Forerunners. They are a common fixture on ice-worlds once used by the Lifeworkers to house vast rehabilitation complexes, and were used in the Forerunners' heyday to provide access to the empire's knowledge networks.

• Amasa
• Boundary - located under the township of Tyrrhen
• Genesis (The Gateway)
• Kamchatka
• Juvedai
• Strilun IV
• Zehar VI

History

Genesis gateway

The Forerunners constructed Lithos gateways across the galaxy prior to the firing of the Halo Array at the end of the Forerunner-Flood war. One such installation was hidden on the shield world of Genesis, nicknamed the Gateway. The Lithos on Genesis was hidden in the planet's coral highlands and rarely used, with the hope that the bioreadings in the region would hide its signature. This installation was used by Cortana to secure control of the Domain following her "death" aboard Mantle's Approach during the New Phoenix Incident in July 2557. During the process of taking control of the Domain, Cortana began to awaken Guardian Custodes across the galaxy and summon them to Genesis. She also began to awaken Lithos sites like the one on Kamchatka, which in turn drew the attention of both Jul 'Mdama's Covenant and the UNSC - culminating in a large battle there. Eventually, SPARTAN-II Blue Team were summoned to Genesis by Cortana and encouraged to enter the Gateway, with Cortana hoping to trap them in a Cryptum to keep them safe during her conquest of the galaxy. Covenant forces deployed on Genesis during the conflict there retrieved information about this gateway during their occupation of the site, and ultimately fed it back to High Lord Dovo Nesto of the Order of Restoration, who in turn began to plot about how he could use the Lithos to attain effective immortality in the Domain. Shortly after, Genesis was moved into slipspace by Cortana, making its Lithos gateway inaccessible.

Hunt for the Boundary gateway

Chloe Hall and James Solomon in front of the Lithos on Boundary.

With the Genesis gateway inaccessible, Dovo Nesto instead turned his attention to finding another one of the Lithos' situated across the galaxy. Through unknown means he was able to acquire a tablet of Forerunner origin with Forerunner glyphs inscribed upon it; when analysed and translated, these provided Nesto with the location of a new Lithos site - the human colony of Boundary. Nesto manipulated both War Chief Severan of the Banished and Sali 'Nyon, a remnant warlord who had recently rebelled against Jul 'Mdama, into assisting him with this plan, promising both the position of his right-hand once his godhood was attained. Thanks to information recovered from Reach, Nesto knew that the Domain could only be accessed by an individual with an identical neural pattern to Cortana - such as an identical clone of Cortana's original brain donor, Catherine Halsey. Knowing of the existence of such a clone, Chloe Hall, he counted on the UNSC's determination to stop him that would result in them bringing her to the Lithos site.

Information about the Lithos was first made available to the United Nations Space Command in 2559, thanks to the research team operating on Zeta Halo. Some time following Cortana's re-emergence on Zeta Halo, the research team were able to report back to UNSC command noting their knowledge of the Lithos as a series of domain access nodes spread across the galaxy, similar in nature to the Kamchatka site. However, the team went silent shortly after, with the UNSC unable to ascertain if this information was discovered naturally on the ringworld or after the Created assumed command of the installation. This information was cross-referenced with a number of other Forerunner sites discovered by the Office of Naval Intelligence, though the locations of further Lithos access nodes remained unknown. However, with this information in hand, the UNSC began to look into ways of neutralising the Domain to ensure that once Cortana was defeated, another individual would not simply assume her mantle as a galactic dictator. This research concluded that the Lithos' were only accessible by an individual with Cortana's neural pattern - something which was available thanks to Chloe Hall. ONI contracted ex-SPARTAN-II James Solomon to kidnap Chloe from her residence on Cascade and bring her to Boundary.

It was through 'Nyon's Covenant by which the Swords of Sanghelios came to learn of the Lithos, having attached a relay mite to a battlecruiser in 'Nyon's service and eavesdropped on their communications. The information they uncovered did not inform the Swords what a Lithos was, but was enough to alert them of the threat and cause them to seek assistance from the UNSC. Shadow of Intent deployed to Venezia alongside a UNSC superheavy cruiser UNSC Victory of Samothrace with the intent of capturing Nesto to interrogate him and find the Lithos' whereabouts. Unfortunately, an intervention by Severan and the Banished meant that this attempt was unsuccessful, though the allied task force succeeded in capturing a Sangheili guard who gave up the Lithos' location on Boundary during his interrogation by Jai-006 and Tul 'Juran. ONI commander Jilan al-Cygni then deployed to Boundary aboard the prowler Akkadian to scan for the Lithos there, while Victory of Samothrace was given command of Battle Group Omega with the goal of doing anything they could to either control, or deny, the Lithos to the enemy. The initial plan was for Akkadian to rendezvous with James Solomon and Chloe Hall and then integrate with the Lithos themselves, granting the UNSC control of the Domain. However, when the Banished fleet retreated from the assault on Earth on December 12, this plan was altered. Victory of Samothrace moved to follow, arriving at Boundary on December 14.

The Banished were able to quickly ascertain that the Boundary Lithos was buried under the township of Tyrrhen and occupied the site, deploying a flame-bore to begin the work of excavating the artefact. They were able to discern the location thanks to a sensor sweep done by Heart of Malice, which detected only one large Forerunner structure on the planet. The excavation was interrupted by the arrival of Battle Group Omega on December 14, which engaged the Banished fleet for a short time before being reinforced by a much larger fleet sent from Earth. The ensuing Battle of Boundary was a massive engagement fought between Severan's Banished fleet and the UNSC, with Sali 'Nyon's armada later arriving in the system. At first the Banished and Covenant held an uneasy alliance, though this quickly broke down once Severan realised that he had been deceived by Dovo Nesto.

Once it became clear the Boundary Lithos would not be feasible for the UNSC to capture, Victory of Samothrace was ordered to conduct an orbital strike on it with its augmented Magnetic Accelerator Cannon, denying the Lithos to both the Banished and the Covenant.

List of appearances

• Halo: Empty Throne (First appearance)