Editing Composer

The Composers were originally designed as a means by which to extract the mental pattern (commonly known as an essence) of a biological being of sufficient neural complexity and converting it into data by broadcasting high-energy fields of entangled sympathies. The process, which was not fully understood by even its Forerunner creators, utilized [[neural physics]], a science mastered by the [[Precursor]]s — one of select few Forerunner technologies to do so. According to the original design, the Composer would allow old Forerunners to transfer their essences into younger bodies or directly into the [[Domain]]'s vast realms of information.{{Ref/Reuse|wp composer}}{{Ref/Note|''[[Halo 4: The Essential Visual Guide]]'' and Halo Waypoint's Universe entry describe the Composer's original function as granting the Forerunners immortality by transferring old essences into youthful bodies, implying that Forerunner medical science had not overcome senescence. According to ''[[Halo: Cryptum]]'' (page 47) along with a number of other references throughout ''The Forerunner Saga'', the Forerunners were functionally immortal given regular access to [[Forerunner personal armor|personal armor]], could remain youthful indefinitely and died only by accident or in battle. However, it is known that Forerunners could age under certain circumstances, even if such aging was unlikely to result in death: after 1,200 years of self-neglectful isolation, the [[Confirmer]]'s skin became mottled with bulging veins, his fur fell out, and his teeth fused together. The issue of Forerunner mortality by old age is not addressed when the Composer's origins are described in ''[[Halo: Silentium]]''. In ''Halo 4'' the Librarian states that the Composer would have made the Forerunners immortal, although this may be interpreted as ''true'' immortality and invulnerability to the Flood, as opposed to the [[Wikipedia:Biological immortality|biological immortality]] the Forerunners already enjoyed thanks to their use of body-assist armor.}} The technology was worked on in obscurity for centuries. In the latter days of the [[human-Forerunner wars]], after the Forerunners' first contacts with the [[Flood]], [[Master Builder]] [[Faber]] took note of the Composers and planned to use the devices to cure the parasite's victims.{{Ref/Reuse|wp composer}} The plan was to save those afflicted by the Flood by scanning their patterns and removing any traces of the Flood from the digital essence, which would then be imprinted on a new, artificially constructed biological body devoid of Flood infection. However, the process was highly flawed. In addition to being extremely painful to the individuals undergoing the process, all attempts to restore the essences to biological form failed as the artificial bodies would quickly decay and inevitably die.{{Ref/Reuse|string3}} For this reason the Forerunners quickly abandoned the Composers after the first experiments.{{Ref/Novel|Id=pri271|Pri|Page=271-272}}{{Ref/Note|Id=whole|In ''[[Halo: Escalation Issue 9]]'', the monitor [[859 Static Carillon]] indicates that the human essences composed in New Phoenix are being "added to the whole" in accordance with the original design for the Composer, introducing fear, rage, and confusion. This implies that composed patterns are uploaded to a central intelligence, though whether this applies solely to the Promethean Knights or to all who undergo composition is unclear. Nonetheless, the notion of composed essences being incorporated into a gestalt mind is not mentioned in prior media.}}

As witnessed on [[Installation 07]], Flood victims subjected to Composer processing were able to retain their individuality,{{Ref/Novel|Pri|Page=325-326}} but the Flood would continue to rot and deform their physical bodies, the infection having survived the destruction of the original biological body and then resumed in the new one. The Forerunners attempted to slow down this process by wrapping the afflicted individuals' bodies in a form of supportive harness flowing with energy,{{Ref/Novel|Pri|Page=322-323}} but the victims would still continue to deform beyond recognition and eventually expire or succumb to the Flood. Similarly, when the [[Gravemind]] used [[Logic plague#Biological beings|corrupted]], Composer-processed essences imprinted on living human bodies as messengers to the [[Librarian]] in her final moments on [[Earth]], the humans' bodies would rapidly decay and soon die.{{Ref/Novel|Sil|Page=320-323}}

As revealed by the [[Haruspis]], the Composer's power burned away the effects of the [[logic plague]] in anyone that it was used upon, freeing them of the Gravemind's corruption.{{Ref/Novel|Id=Epi20|Epi|20}}

===Essence preservation===

In the case of the [[Ur-Didact]]'s [[Promethean Knight]]s, the extracted neural map was used as the basis for [[artificial intelligence]] constructs in a manner similar to [[Cognitive Impression Modeling|the creation]] of human [[smart AI]]s. These intelligences contain many of their original memories and sometimes even portions of their personality, but otherwise behave within the limits of the duties assigned to them.{{Ref/SpOps|Id=memento|[[Memento Mori]]}} These essences were stored in imprint matrices known as [[Durance]]s, similar to the devices traditionally used to contain the last mental impressions of a deceased Forerunner.{{Ref/Book|H4EVG|Page=134}}

===Immunization===