The prophecy of gray is the main prophecy in the first book.
It reads:
Beware, Underlanders, Time hangs by a thread.
The hunters are hunted, white water runs red.
The Gnawers will strike to extinguish the rest.
The hope of the hopeless resides in a quest.
An Overland warrior, a son of the sun,
May bring us back light, he may bring us back none.
But gather your neighbors and follow his call.
Or rats will most surely devour us all.
Two over, two under, of royal descent,
Two flyers, two crawlers, two spinners assent.
One gnawer beside and one lost up ahead.
And eight will be left when we count up the dead.
The last who will die must decide where he stands.
The fate of the eight is contained in his hands.
So bid him take care, bid him look where he leaps,
as life may be death and death life again reaps.
Fulfillment
Beware, Underlanders, Time hangs by a thread.
The hunters are hunted, white water runs red.
When on his first night, Gregor escaped Regalia from the docks, he encountered the Gnawers Fangor and Shed. As the Gnawers are considered the hunters of the Underworld, when the Regalians fought them to rescue the Warrior, they became hunted. After they were killed, to delay the discovery of their deaths, the Regalians then threw both Gnawers into the white water of the river.
The Gnawers will strike to extinguish the rest.
The hope of the hopeless resides in a quest.
Shortly after, the Gnawers were found and in revenge, they began amassing troops, declaring war on Regalia. The army was so large that there would not have been any way to defeat them without their wiping out most Humans. Also, the Warrior, Gregor had lost hope that he would be reunited with his father so in order to save both Regalia and his father, he embarked on a quest.
An Overland warrior, a son of the sun,
May bring us back light, he may bring us back none.
But gather your neighbors and follow his call.
Or rats will most surely devour us all.
Not only is Gregor a son of the sun by being an Overlander, he was also a child who was a son of another Overlander. If the other species did not join his quest to bring back "light," something synonymous with life, the rats would more than likely kill everyone in Regalia as well as their allies.
Two over, two under, of royal descent,
Two flyers, two crawlers, two spinners assent.
One gnawer beside and one lost up ahead.
And eight will be left when we count up the dead.
Gregor the Warrior and his sister Boots both hail from New York City in the Overland. Henry, next in line to the Regalian throne (after Luxa) and Luxa (Queen in waiting of Regalia) live in the Underland and serve as members of the royal family. Accompanying them were Ares, Henry's bond and Aurora, Luxa's bond, both being fliers. After Boots was honored by the Crawler's sacred dance, Tick and Temp both joined as the Crawlers. Upon meeting Ripred, the Gnawer that would fight beside them, two Spinners, Treflex (who died immediately due to battle wounds) and Gox joined with them. The main goal of the mission was to locate Gregor and Boots' father who was both mentally and physically lost ahead on the journey.
Counting the participants of the prophecy, there were twelve total, a number that was cut down with the deaths of Treflex, Gox (by the hand of King Gorger,) Tick (by an unnamed rat,) and Henry, to eight.
The last who will die must decide where he stands.
The fate of the eight is contained in his hands.
So bid him take care, bid him look where he leaps,
as life may be death and death life again reaps.
Tired of being allied with Vikus, Spinners, and Crawlers, Henry decided to stand with the rats. Because of his eagerness to get the Regalian throne, he attempted to help the rats, only to leap off a ledge to his death. Believing Ares would catch him, he did not pay attention to his surrounds, only learning at the time of his death that he was doomed. This was because Ares was busy saving Gregor, who decided that he had to take a stand, leading the rats off a cliff. Because of this, King Gorger was killed. When the news reached the rats laying siege to Regalia, they scattered, ending the war.