The first time Itachi noticed the string around his wrist it was almost too late. With the situation surrounding his people rapidly coming to a boiling point, the loss of Shisui was very nearly the event which would have pushed him over the edge to accept Shimura Danzo 's crazy plan. Instead it became the event which saved them all.

Watching his best friend tear out his own eye and cast himself to an inevitable death over a waterfall awoke the mythical formation of his Sharingan known as the Mangekyo Sharingan. On his way back home from that grisly scene, his legs wanting to stumble even as his pride wouldn 't let them, Itachi saw something with those new eyes for the very first time which changed his entire life. He saw a pretty red string tied around his wrist.