"I will have your eye," Danzo says.
The man is evil. Shisui knows this, intellectually as well as intuitively. But although his scalp itches and his fingers twitch—to run, to hide, to kill?—fourteen-year old Shisui lowers his eyes and nods.
And thus, fourteen years of social conditioning defeats the primal instinct to survive. Shisui dies. Danzo moves onto the next Uchiha.
Danzo is a mastermind. He plots, he manipulates. He takes steps that unfurl, one after another, like a flower. This is Danzo's talent, one he grooms, trains, abuses. The thing is, even the most oiled tool can betray you sometimes.
Especially when it comes to tools that are metaphysical rather than iron.
Danzo makes two mistakes. The first is not so much a miscalculation as it is an utter trick of fate.
It is this: Hyuuga Hiashi is walking. He walks through the woods, far from his Branch House guards. He walks, Byagukan activated, not so much out of necessity as for the practice. It's been a long time since Hiashi's walked the thin knife edge of active duty, and although he doesn't miss it, he can feel himself getting old.
Hyuuga Hiashi is walking when he sees, in the distance, the Uchiha heir.
Uchiha Itachi is training. As always, he trains with complete utter focus. That is not to say he is training calmly. Because, behind each of his fine, scissor-quick movements, there exists absolute helpless rage. Far above him, a raven watches with Shisui's eye.
Hiashi watches too, and even with his great eyes, he sees not the rage and only the absolute power. But it is enough.
So this the great Uchiha Itachi, Hiashi muses. The boy prodigy everyone has spoken of.
That night, at a meeting that Hiashi has secretly been dreading, the Hyuuga Elders shout, "She is weak!"
Here, Hyuuga Hiashi steadies his sweaty palms against his lap. At seven years old, it is already obvious that Hinata lacks the lucky star to be an unparalleled killer. Meanwhile, at eight, it is also already obvious that Neji is a genius, the kind the Hyuuga have not seen for at least three generations.
Hiashi's wife is gone. But she has left behind another daughter, one who Hiashi secretly vows will never have to suffer what Hinata is blindly suffering now. But that is another issue. Now, they are talking about his eldest now. They are murmuring about seals and marriage, because even if Hinata's divine hands are useless, she still has her ovaries.
"Enough," Hiashi demands.
Silence, but not the peaceful kind. It is the kind that demands an answer. The shinobi world pulls no punches for children, not even for seven-year-old girls.
"She is young," Hiashi says.
The Hyuuga roar. It is not an adequate answer. Hiashi needs more.
Danzo's second mistake is the Third Hokage. Danzo miscalculates the Third Hokage's gritty idealism, still present despite all the stains and tears. Danzo also miscalculates the Third Hokage's power. He forgets to give credit to an old man who has navigated the cesspit of shinobi politics not just once, but for a second term. But most of all, Danzo miscalculates the Hokage seat. For all of Danzo's ROOT spies, there are things that only a Hokage would know.
For example, only the Hokage remembers that the Hyuugas were the original opponents of the Uchiha ghetto. Despite their personal feelings (everyone knows the Sharingan is a bastardization of the Byagukan), only the Hyuuga truly understood that a ghetto was the first step on a slippery slope, a slippery slope that ended in the genocidal campaigns now raging through the other shinobi countries. While the other noble clans of Konohagakure had made some noise on the Uchiha's behalf, their techniques were mostly crafted things, things that other humans can understand and thus not fear; not bloodlimits. And so, not even the Akimichis and the Aburames* understood what the Hyuuga knew: that humans fear what they do not understand, and bloodline limits are secrets, are mysteries bubbling at the genetic level.
The Hokage is also the only one to know that the Hyuuga are actually very much aware of ROOT. Although Danzo and the Elders would throw a fit if they knew, the Hyuuga have their own highly sophisticated spy system. It is a system woven by ties of loyalty and blood that trump even Danzo's inky death-tattoos-beneath-tongues, and aided by a blood limit even Danzo can't get his hands on. The Hokage knows of this only because he himself has had to rely on this network in the past, during the few times he has had to act behind the Elders's back. Although the Hyuuga still do not trust him (he is outsider, not one of their paranoid own), they trust him more than most.
So, ultimately, Danzo's mistake is this: Hiashi Hyuuga is called into the Hokage's office, ostensibly for consultation on Hyuuga involvement in the ANBU. In between two cups of tea and a finger's length worth of tobacco, a plan is made. The Hokage needs a third actor to tip the scales, muddy the water, and Hiashi needs to protect his daughter.
Within twenty four hours, a scroll appears at the Uchiha Compound. It is a beautiful scroll, of tasteful maple, grounded ink, and pure white. Within the first few characters, Hiashi derails Danzo's plans (and the Uchihas's plans and the Tobi's plan, but no one knows this yet) enough so that in the time that Uchiha Itachi expected to find himself standing over his family's corpses, instead he finds himself standing over the quivering mousy form of a seven year old girl.
The few characters propose this:
Uchiha Itachi is to be married into the Hyuuga Clan as consort to Hyuuga Hinata, Hyuuga Heiress and future Hyuuga Head.
And thus, history is forever rewritten.
*The four noble clans of Konohagakure are the Aburames, the Akimichis, the Uchiha, and the Hyuuga.