The Negotiations Universe is a TCB fanfic series written by Rated Ponystar, based on Blaze's original story. Much like The Conversion Bureau: Not Alone and The Conversion Bureau: The Other Side of the Spectrum, Negotiations and its sequels serve to deconstruct the TCB universe and its various tropes.
The series takes place on earth after humanity goes to war against and (with help from Equestrian defectors) triumphs over ponykind to stop their ponification crusade. With Equestria at humanity's mercy and most of its leadership either dead or incapacitated, Twilight Sparkle has to find a way to reach peace between the two sides. The series is notable for its much more serious and realistic tone compared to other TCB stories.
When the series grew to popularity, Rated Ponystar gave his blessing for side stories to be written in the verse.
The stories are as follows:
(This summary contains unmarked spoilers. Read at your own discretion.)
Negotiations takes place shortly after the war between Earth and Equestria. Equestria appeared on Earth in the year 2036 and had opened the Conversion Bureaus all over Earth. However, after ten years passed by and humanity became privy to the changes in the newfoals, Celestia's intentions became clear and war was declared. The war stretched on for five long years and although they had magic, the potion, and the barrier, Equestria is handily and thoroughly defeated - the Crystal Empire (along with several other towns in Equestria) is destroyed, Luna and Cadence are dead, and Celestia is comatose due to using every bit of her power to protect the remaining ponies from a brutal aerial assault, leaving Princess Twilight Sparkle to (as the title states) negotiate a truce with the UN and save what remains of her nation. Swallowing her pride and prejudices, Twilight gains a new perspective on humanity in the process, as well as realizing (and admitting) the horrors of the potion and most especially the horrific fate that likely befell all of Equus without the princesses there to move the sun and moon.
Reunited takes place five years after Negotiations. After losing her whole family (sans Spike) along with Rarity and Pinkie Pie to the war while Applejack and Rainbow Dash refused to accept Equestria's surrender and joined the Equestrian Freedom terrorist group to keep the fight going, Twilight desperately needs someone besides Spike who can help share the weight of her burdens and seeks out Fluttershy years after they parted on bad terms due to the latter defecting to aid humanity in the war (with Discord following suit). Despite her anxieties, Twilight successfully rebuilds her friendship with Fluttershy, who is now married to a human and a mother to three adopted children.
Truth takes place one year after Reunited. Celestia has awakened from her coma and put on trial for her crimes against humanity. She is sentenced to be executed, and Twilight, seeking answers, asks Celestia why she did what she did. After some initial resistance and refusal to divulge her reasons, Celestia agrees to tell Twilight everything in exchange for the latter to keep them secret so as to not destroy the fragile peace between humanity and the ponies. Twilight reluctantly agrees. Celestia then reveals that three hundred years before Nightmare Moon's return, she discovered that Equus' sun was slowly dying and so she dedicated herself to finding a way save their entire world before it was too late. First, she tried to find a way to extend the sun's lifespan, but when that proved fruitless, she opted for the "homeworld evacuation" route. She searched high and low for a suitable dimension that could house their world and eventually did in the form of Earth's dimension. Although she had hoped to transport all of Equus there, she didn't have the means to do so, and her options boiled down to either wasting even more precious (and very limited) time trying to find a way to save their entire planet, or sacrifice all other life on their homeworld to at least guarantee the survival of her nation and subjects as opposed to nothing at all. Celestia chose the latter option. As for the potion and the conversion bureaus, those came about because Celestia was convinced coexistence with humanity (a species she saw as barbaric and destructive) was impossible and she didn't want Equestria's culture to be tainted by their influences, and she was convinced it was all for humanity's own good anyway. Having finally gotten the answers she sought, Twilight asserts that although she understands and even sympathizes (to a limited extent) with Celestia's position, she absolutely cannot forgive her former mentor for leading Equestria into an unnecessary and entirely avoidable war that caused so much loss and suffering because she chose to believe in the worst of humanity and disregard all of their good aspects rather than try to make peace. Nevertheless, Celestia states she doesn't regret doing what she felt was necessary to ensure the continued survival and preservation of Equestria and the ponies. Twilight leaves with a bitter farewell and Celestia is executed shortly afterwards.
Useless centers on Applejack, a leading figure within the Equestrian Freedom Fighters and now a very bitter and hollowed out shell of a mare, coming to terms with what she's lost over the years, including her whole family and her lost friendships (to the point that she and Rainbow Dash attempted to assassinate Twilight). She and Rainbow Dash, knowing that this is the end for them, have one last drink together and reflect on their mistakes and the sad realization that their efforts were ultimately useless. The two mares decide to at least go down fighting, only for a random soldier to find them and gun them both down.
Rest centers on Spike, several years into the future. Twilight is now an old mare who is dying of cancer (which she left untreated so as to continue working on a cure for the ponification potion). As Spike prepares for the approaching death of his adoptive sister, he encounters Discord (who is a beloved celebrity on Earth) and the two have a talk on what to live for since they'll inevitably outlive most humans and ponies, and the two of them dedicate their lives to making sure history is remembered and preserve the peaceful coexistence between ponykind and humanity. Twilight, after seeing a candlelit vigil for her outside her home, is able to pass on peacefully, knowing that humanity and ponykind love and have forgiven her.
Future is set over three hundred years after Rest. Spike is now a history teacher, having dedicated his life to preserving knowledge about the details of the war. Background details reveal that Equestria became a democratic republic and has adopted several human customs and holidays, while a new potion has been developed that allows for temporary transformations. And due to Earth's lack of magic, DIscord is no longer immortal, and is approaching death himself. Despite his mission giving him a fulfilling sense of purpose, Spike feels lonely, as his friends are all dead and he'll outlive all his new ones. He is also struggling with his growing attraction to a human artist named Rebecca.
The Negotiationsverse (as it's called by Rated Ponystar and fans) is a deconstructive take on TCB. It's more in the vein of Not Alone as a serious analysis of how the scenario would play out realistically. Ponification is explicitly stated to profoundly change humans' personalities and become almost blindly and blissfully happy. Twilight compares them to Starlight Glimmer's brainwashed townsponies at one point and even when she was pro-ponification, she admits that they unsettled her.