Neural transmission

"Eventually the Didact felt his essence breaking gently apart and sinking into the Domain's quantum field and the neural lace that made up its infinite framework. He felt its immensity, its fundamental connection with the Cosmos. It was older than the galaxy, perhaps older than the Precursors themselves. It lay over everything. And its lace was his path upon which to travel. He sank deeper, feeling cocooned, as though space and time had crept up behind him and folded its arms around him, embracing him, sinking into each infinitesimal particle of his essence, becoming his essence just as he became space. After a while, he began to sense the peculiar oscillation between absolute stillness, as if time had ceased, and the astounding speed of the universe expanding. Was he motionless as the stars rushed past him? Or was his consciousness moving so fast that he left time and space behind, racing the expansion and winning, universes and alternate realities blurring by one after another? Haruspis's song gently reigned his intention back in, and the Didact remembered where he wanted to go, and the one he wanted to speak to. Zeta Halo. Cortana. In an instant he was there. In the ring's Conservatory, all the parts of him pulling back together. Time was sluggish here, his thoughts and movements lagging as he gradually oozed out of space like a snake shedding its skin, leaving behind the energy that clung to him and the residue of all the worlds and realities he'd gone through to get here. The entry back into his reality took more time than the transit itself."

— Description of the Didact using neural transmission

Neural transmission, also known as neural physics transmission, was a method of travel using Precursor neural physics.

Overview

According to the Haruspis, neural transmission began by achieving deep synchronization with the Domain, similar to reaching the highest levels of xankara. While this would normally take hundreds if not thousands of years to achieve, a Haruspis was capable of accelerating the process. The being attempting neural transmission had to turn their thoughts away from individuality to unity with the space around them, all things and the Cosmos. Eventually, their essence would break gently apart and sink into the Domain's quantum field and the neural lace that made up its infinite framework. The Domain, which was older than the galaxy and perhaps even older than the Precursors themselves, lay over everything and the being traveled down its neural lace to their chosen destination. Returning was described as allowing the being's consciousness to be buoyed along the steady tide of Living Time back to the Domain.

The Flood fleet using neural transmission was described as crossing alternate realities to achieve a near-instantaneous rate of travel. However, neural transmission had such a slow rate of rematerialization that the fleet was left vulnerable to attack.

Neural transmission took the user through countless alternate universes and realities to reach their destination, allowing them to see numerous potential outcomes for a situation, although only the eventuality that came to be mattered. This enabled the being to nudge events things towards one particular eventuality, even if just by planting a "seed" with those involved in the events.

When the Ur-Didact used neural transmission for the first time with the help of the Haruspis, he traveled across the Cosmos itself and other realities, nearly losing sight of his intended destination before the Haruspis's song pulled him back. The Didact was described as not just traveling through those realities or they through him, but he had seen glimpses of past, present and future and its millions of possibilities. The Didact wondered if what he witnessed though neural transmission was just a taste of what the Librarian had tried to explain to him about the nature of Living Time.

In the case of Forthencho, neural transmission didn't just allow him to observe the Battle of Boundary, but also connected his consciousness to the lives of those participating in the battle. Forthencho could feel their perspectives and their deaths, and it took him a moment to center himself as it was far too easy to get lost among them. The destruction of the Boundary Lithos and the loss of so much life to connect to caused his presence to begin to fade and the Domain to start "tugging" Forthencho back like a safety cord.

History

During the final days of the Forerunner-Flood war, the Builder Security-trained Warrior-Servant fleet commander known as the Falchion witnessed the arrival of more than a hundred thousand Flood-infested Forerunner ships through space via neural transmission. Falchion took advantage of the vulnerability that the fleet experienced from the slow rematerialization to attack. The Ur-Didact later read this report and only remembered it because of the nine Builder-trained fleet commanders, only the Falchion had remained staunchly loyal to the Didact during the nine-hundred-year period in which he trained and fought.

Following the defeat of the Warden Eternal, the Haruspis helped the Didact to use neural transmission to reach Cortana on Zeta Halo. Overwhelmed and awed by the experience, the possibilities of the future had rushed by too fast for the Didact to delve deeper into any one thing, as he hadn't known how to slow down enough to look deeper. However, the realizations and impressions along with the Didact's own instincts told him that force would not result in the best outcome with Cortana. As he was only a Domain essence, after coalescing, the Didact entered into and travelled through Installation 07's systems to the Silent Auditorium. After speaking with Cortana, the Didact returned to the Domain as Atriox and Joyeuse both approached.

Having seen many possibilities and eventualities as he crossed through countless alternate realities and universes during his neural travels, the Didact was left eager to see whether the seeds that he had planted had indeed played a small part in leading to an eventuality. Indeed, the Didact had helped Cortana to decide to sacrifice herself to stop Atriox. After discovering this, the Didact was content to remain in the Domain and no longer get involved in the affairs of the physical world.

On December 15, 2559, Forthencho used neural transmission to observe the Battle of Boundary. Neural travel showed him numerous possibilities and outcomes for the battle, specifically the UNSC Victory of Samothrace's MAC strike, although the only one that mattered was the one that would take shape. Ultimately, the Victory of Samothrace destroyed the Boundary Lithos with its MAC strike, killing thousands of Banished and Covenant. The Domain subsequently began "tugging" Forthencho back like a safety cord while his presence had already begun to fade with the destruction of the Lithos and the loss of so much life to connect to. With his mission complete, Forthencho returned to the Domain.

List of appearances

• Halo: Epitaph (First appearance)
• Halo: Empty Throne