Naruto finally finds Sasuke, and a battle ensues between the two ninjas. Naruto cannot fathom the reasons driving Sasuke to seek ever more power—through Orochimaru's seal, which continues to spread—nor why, above all, he turned his back on his friends and renounced Konoha. A long flashback then follows to Sasuke's childhood, revealing the relationships he had with his genius brother, Itachi, and his father, who was extremely demanding of his sons.