Firmament

The Firmament, or formally the First and Final Firmament, were the species who ruled over the 10,000 Dawns, playing a role equivalent to that of the Great Houses for the Totality, with whom they signed the Christmas Needle Agreement.

Like them, they were immortal thanks to the ability to be reborn in new bodies when their current one was killed, and they could travel through time, space and dimensions in advanced, dimensionally-anomalous spacecrafts. They also had renegades, such as Lady Aesculapius.

Origins
Graelyn Scythes was told at the Christmas Needle Agreement that the Firmament "weren't actually remotely the same species" as their equivalents in Auteur's universe; the two groups had "just ended up with the same job" for their respective realities, in a kind of convergent evolution. (PROSE: White Canvas)

Bid for the Book of Books
The Firmament were ruled by the Arbiter of Eternity. Over his unthinkably long life, he exhausted every book that had ever been written in the 10,000 Dawns and lacked for entertainment. The Arbiter of Knives told him of the Book of Books, a supernatural, infinitely-long tome which had found its way to another universe alongside a cache of books from the 10,000 Dawns, which described the great space-time war of the other universe as fiction. Though leery of attracting the attention of their counterparts in that universe and starting an interdimensional war, the Arbiter of Eternity authorised the mission so long as the Arbiter of Knives understood that he would deny all knowledge of it in case anything went wrong.

The meeting was spied upon by operatives of the Great Assimilation and Dawn, both of whom followed the Arbiter of Knives to the Totality. Dawn were the ones to find out how to access the books (which were being held by the New York Public Library in the 21st century): they prevailed upon friends in low places to ensure that events surrounding a woman native to this universe, Rachel Edwards, would not be monitored for a few days. However, the Arbiter caught wind of this, as did the Assimilation spies and local aliens known as the Strid — all of whom then tried to abduct Rachel. Eventually, the Arbiter fought her way to the room were the books were held, easily taking out representatives of local powers such as people in silver jumpsuits, people in golden robes and people with masks who'd guilelessly shown up for the books with no knowledge of the interdimensional interlopers, and wanted to get their hands on the intel contained in the fictional books. The Strid, however, were the ones to take hold of the Book of Books, and decided to auction it off between the three 10,000 Dawns factions now represented. The Arbiter offered the Strid their own planet in the Dawns, an offer matched and then outbid by the Assimilation, while Dawn refused to negotiate with the murderous aliens. In the end, however, Rachel managed to outwit the interdimensional visitors by threatening to kill herself, which would remove their protection and thus call down the wrath of the "Firmament-equivalents" upon them. Accepting she had been beaten, the Arbiter retreated aboard her Factory of Crystal. (PROSE: Rachel Survived)

The Christmas Needle Agreement
When Auteur, a rogue member of the Firmament's counterpart species in another cosmos, decided to turn the 10,000 Dawns into fiction as part of a plot to end the war in her universe, she tricked the Original Mammoths into believing that the Firmament were a threat to them. The Original Mammoths sent the painted warriors to the Dawns in a surprise attack, and the warriors abducted the Firmament out of time, with only Lady Aesculapius initially escaping. Taken back to the mammoths' alter-time realm, the Firmament, soon joined by the rest of the Dawns' population, were frozen in a single moment of itme by the mammoths until they were turned into fiction by Auteur alongside the mammoths themselves.

Subsequently, they appeared as antagonists within the action film series starring Archimedes Von Ahnerabe. They were depicted as an "evil cult", with one member played by Brendan Frasier acting as the villain of Archimedes: Skymetal, where he tried to blow up an underwater city. After seventeen years in Auteur's Town, Graelyn Scythes figured out what was going on and eventually managed to undo all of Auteur's fictionalisations using her own weapon.

Subsequently, representatives of the Firmament attended a summit at the Needle in the other universe, where various powers from each reality had gathered to negotiate a Christmas Needle Agreement that would prevent any such unprovoked attack repeating itself. At the gathering just before the negotiations began in earnest, the Firmament representatives were spotted by Graelyn having "a very heated chat" with ambassadors of the Bookkeepers. (PROSE: White Canvas)