The First Plague
Sunny felt a headache approaching.
Something was very wrong here.
How could the Six Plagues exist?
The Great River was a time loop — just like Aletheia's Island had been, but also different.
On Aletheia's Island, time moved in a circle. A single day endlessly repeated itself, and a new cycle started each time that day ended. The Great River, however, was a bizarre place where time and space were one and the same — it flowed from the future into the past, and so, those who traveled it were also traveling across time.
The cycles of the Great River did not start once a certain period of time passed. They were both a measure of time and a measure of space — to reach a new revolution, a person had to travel all the way to the Estuary, which was also the Source, and cross the boundary between the past and the future.
Then, they would be sent to the point in time and space when they had first entered the Tomb of Ariel. So, if the Chain Breaker sailed past Verge and braved the Source, the members of the cohort would be sent to different places on the first day after they had entered the Nightmare.
Sunny would find himself on a piece of flotsam, Nephis would be stranded on the corpse of the Black Turtle, Cassie would return to Fallen Grace on the day the other sybil succumbed to the Defilement, and Jet and Effie would be back to living the harsh lives of the River Nomads.
Sunny shifted slightly.
Still, it did not explain how both the members of the cohort and the Six Plagues could exist at the same time. If their version from the previous cycle had braved the Source — on purpose or by accident, while searching for the entrance into the Estuary — they would have disappeared.
More than that, the Plagues had been rampaging across the Great River for decades, perhaps even centuries. How could that be?
'Well, why not? There's all kinds of weirdness happening with time in the Tomb of Ariel. Do I really want to doubt that something like that is possible?'
Especially now that Sunny knew about the Source — a misty place where the past and the future met, and where the meaning of time lost all reason — he could not be surprised by anything.
What would happen, for example, if someone entered the Source, but then turned back and left the way they had come instead of crossing the boundary of the future? What would happen if they left from a different point than where they had entered? What would happen if they stayed inside the Source for a while, allowing the current to move past them?
He did not know.
Sunny did know one thing, however.
The method of starting a new revolution might have been different from Aletheia's Island, but its effect would be the same.
Once someone returned to the past, their memory of the previous cycle would be erased. Their soul would be restored to how it had been before. No signs of them having traveled the Great River in the past would remain.
Which meant…
Sunny shivered.
'Not again, please!'
The words he had shouted while waking up, on the first day in the Nightmare, echoed in his ears.
'H—how… how many times have we challenged this Nightmare?'
The existence of the Six Plagues proved that there had been at least two cycles. But there could have been more. Ten cycles… a hundred cycles… a thousand cycles…
There was no way to tell. Since no one remembered the previous revolutions, nothing would change when a new one started. They would repeat the same actions over and over again, just like Jet had fought and been killed by UndyingSlaughter over and over again.
Until Sunny arrived, and became aware of the loop.
Suddenly, he felt his heart beating wildly.
'Wait…'
Despite being trapped in the time loop of Aletheia's Island, Sunny had eventually gained the ability to remember the previous revolutions. He did not know how long it had taken, but at some point, he was assaulted by a persistent sense of déjà vu, and then became fully aware of the loop.
That was because the Sin of Solace was stuck in his mind, and the loathsome sword wraith was somehow immune to the effect of the repeating time.
Sunny felt that he was on the verge of realizing something extremely important.
'The Sin of Solace…'
The Mad Prince was haunted by the odious apparition, as well.
So, if the cohort was trapped in the infinite loop, didn't it mean…
That he would have gained the ability to remember the previous cycles of the Great River, as well?
'D—damnation!'
Sunny's eyes widened.
The Mad Prince… no, perhaps even an earlier versions of himself… would have realized the cyclical nature of the Great River. And from that point forward, each cycle would have been different.
Because Sunny had become a variable.
He must have tried to change things. He must have tried to conquer the Nightmare desperately… and in such a way that none of the members of the cohorts died.
And Nephis survived till the end.
...But, for some reason, he had failed.
Or maybe that mission had been doomed from the start.
Had he become aware of the grand loop before and after becoming infected by the Defilement?
The Defilement, after all… was knowledge. Terrible knowledge that corrupted the souls of those who possessed it. So, even if Sunny reached the Source and returned into the past after being infected by the Defilement, the infection would have returned with him.
Had he gone mad under the mental strain of endless loops first, or had he found the true Estuary and been driven insane by the Defilement first?
Had Sunny been the first of the Six Plagues, and the one who had infected the other five?
In any case…
'So why do I not remember anything? If my version from the previous cycle was corrupted by the Defilement, why is my soul free of it?'
He flinched.
Wasn't the answer obvious?
What could cure the infection of cursed knowledge?
…Oblivion could.
In order to be cured, he had to forget the cursed knowledge before returning to the past.
'The Key of the Estuary.'
A mysterious Memory that had been there, in his soul, when he found himself in the mist on the first day of the Nightmare. A Memory that possessed a passive enchantment that did not seem to have any effect on him.
An enchantment that consisted of two parts — one directed outward, one directed inward.
And which had something to do with the Sin of Solace.
Sunny took a deep breath as the truth of the Estuary Key finally revealed itself.
'It's... a muzzle.'
The purpose of the mysterious Memory… was to prevent the Sin of Solace from sharing any knowledge of the previous cycles with Sunny. So that he never remembered what had happened in the past, and therefore never learned the cursed knowledge of Defilement.
That was one part of its enchantment. The other, much more burdensome part… was meant to make the Estuary Key immune to the change of cycles. To make it remain in Sunny's soul even if he crossed the boundary of the Source and was sent into the past.
That was why the Mad Prince had been so interested in the Great Tyrant slain by the Serpent King in Aletheia's Tower. Because the Tyrant remained dead no matter how many revolutions passed… its death had been made permanent, carrying over from one cycle of the loop to the next.
Back then, the Defiled madman must have already been trying to create the Estuary Key.
To cure himself of the Defilement… and make another attempt to conquer the Nightmare. No, not just conquer it, but do it in a specific way.
To erase the mistake he had made... or maybe the crime he had committed.
'Murderer...'
Sunny gulped for air.
At that moment, he realized something else.
There were only three of the Six Plagues left: Soul Stealer, Torment, and the Dread Lord.
The Mad Prince… was gone.
He did not exist in the Tomb of Ariel anymore.
Because he had crossed the boundary of the Source and sent himself into the past.
He had become Sunny.
