(Timeskip 5 years)
The biggest mass killing took place the previous day in Konoha, an entire clan the strongest on that was slained in just one night by one man, Itachi Uchiha. Just as Itachi finished his mission and knocked Sasuke off, Obito under the disguise of Tobi appeared infront of him.
Itachi: "I will meet you at the 3rd border of Konoha, I still have some unfinished business here."
Tobi: "Hmpfh fine, as you say"
With that he vanished in a vortex of kamui. Itachi then rushed towards the centre of the village completely blending in the night he appeared inside the Hokage's room via a crow shunshin.
Itachi: "Lord Hokage, I have completed your mission but I have spared my little brother. He would be under your care from now on."
Hiruzen: "I will take utmost care of Sasuke, however you would now have to be prepared for facing the hate of the entire village including your brother your path would be anything but easy."
Itachi: "I knew what I was going to face before I accepted this mission and I accept it as my fate."
Hiruzen: "Itachi my final message is be ware of a person who might be extremely hostile to you at any cost if you encounter him leave the place as soon as possible and if situation becomes dire I allow you to reveal this mission you might know who I am talking about it was the same person your Anbu team encountered in which three of your teammates were knocked of including you."
Itachi: "Is he a member of my clan as I distinctly remember those eyes I could not comprehend that info previously but is he an Uchiha with a Mangekyo Sharingan."
Hiruzen: "His identity is kept a secret but you have deduced most of it do what you must do, I cannot reveal to you anymore. Also you should leave now, the Anbu have noticed the situation your pursuit must have begun."
Itachi: "Then I would be taking your leave. Farewell my Lord."
Saying those last words Itachi vanished and the third Hokage exhaled some smoke and turned around to leave when he noticed something. He turned back and stared in the sky and out of nowhere, a black hawk appeared in the night sky slowly wings appeared around him and he began to burn. After a few seconds, when his entire body was almost burnt, his right eye glew red and a pattern of Gömböc appeared in it, the eye started to bleed and crimson blood fell from it until the bird was turned into ashes. Hiruzen was not too surprised seeing this scenario.
Hiruzen: "As expected, so you witnessed it. Now I wonder what your next move would be."
Saying that he returned in his room.
(Pov somewhere unknown in the Land of Snow)
A man, with white hairs a tall shredded muscular build and a tattoo on his neck(which when closely noticed was a curse mark) with just a waist and black pants was chopping wood. When suddenly he stopped and sat down on a chopped tree and covered his face with his hands. He appeared to be frustrated out of nowhere. There was a boy near him cooking something in a pot when he noticed his companion's strange behaviour he questioned him.
Haku: "Kageyama sama is something the matter. Do we have any pursuiters or is it something else."
Kageyama: "Something happened back at my home village.. or should I say my ex-home village. My entire clan was annihilated under the gazes of my teacher and his companions."
Haku was visibly stunned after being told this information.
Haku: "So are you planning to enact revenge against the perpetrators"
Kageyama: "…. No. I have left that life long before my clan and my village, their affairs are no no more of my concerns."
With that he began continuing his work. After chopping some more trees, he began loading the logs back in a carriage and ordered the carriage holders. He was then given a bag of copper coins and the carriage left. Kageyama and Haku then began leaving the place, Kageyama then wore a black Japanese high-collared shirt with the Uchiha clan symbol and then covered himself with a complete black covering thin blanket which covered his entire upper body up till his knees. They went through the forest in a snow storm to a house in the middle of it made up of smooth stone and if noticed closely remanants of earth release chakra could be seen from it.
(Pov in Konoha)
A meeting was immediately called the next day, for the discussion of the actions that took place the previous night. The Uchiha clan was a highly powerful and influential clan was eradicated in one night by a single person. Discussions about increase in security and how the village monitoring should be reformed was taking place. It took a while for the meeting to be adjourned however, Danzo remained alongside Hiruzen when the meeting was finished. After everyone left, a small smirk appeared on Danzo's face.
Danzo: "Well its over, I bet sensei must be so happy in his afterlife. Ha ha"
Danzo finally allowed a laugh to break on his face after years infront of his friend this showed what an achievement he considered the event which just took place.
Hiruzen: "I never wanted to see such a day. Danzo I want you to remain under covers alongside the best of your men until I say so there is someone whom I am expecting to come after you."
Danzo: "I know ..Itachi, well he came babbling about how I should stay away from his brother or he would leak classified information about the village. I get it I would not lay a finger on the last Uchiha unless he steps out of the line and I also know about that other man alongside him well he is not a threat for now."
Hiruzen: "Well they are less of my concern for now, this man I am talking about is.. on of my own personal agent. Perhaps the best that ever appeared he is not in the village and we have not been in contact for a while."
Danzo: "An agent you say.. Kakashi Hatake or Jiraiya who got the truth about this event."
Hiruzen: "None of them and that person is by far more dangerous than them, even I am not sure if I could save you from him if he is fully determined to kill you. Though it is possible that my worries are appearing out oof nowhere and he might not even bat an eye on you but my instincts have always been cautious."
Danzo: "Who is this agent and why can I not recall such an agent."
Hiruzen: "Who he is, is not something you should concern yourself with. Not many people have lived to tell the tale after knowing the answer."
Danzo: "Stop playing words with me. Just answer me"
Hiruzen: "Well I answered you enough, now I need to check if he is after you or not so cut me some space would you."
Danzo: "Hiruzen such matters must be discussed among us elders, your secrets should atleast be known to us, its not just a matter between us this involves the village. Atleast be transparent for it."
Hiruzen turned back and began walking towards the window liting another cigarette.
Hiruzen: "I will, when I deem it the correct time to. For now I order the meeting to be adjourned in case of any important matters you would be informed."
Danzo gritted his teeth and left. But a question lingered in his head about who this person is and why is Hiruzen, arguably the strongest ninja the world currently has to offer, so subjugated by him.