Sasuke left the Hidden Leaf Village (Konoha) to gain the power needed to avenge his slaughtered clan and kill his brother, Itachi. Believing his peaceful life and friendships in the village were making him weak, he defected to train under the rogue ninja Orochimaru.
The Sasuke Recovery Mission (or Sasuke Retrieval Arc) is a pivotal storyline from Part I of Naruto. It follows Sasuke Uchiha's defection to Orochimaru's Sound Village and the Leaf Village's desperate attempt to retrieve him before he crosses the border.
The epic climax of Naruto Part 1 takes place across episodes 128 to 134, culminating at the Valley of the End. This dramatic clash sees Naruto fighting desperately to prevent Sasuke from defecting to Orochimaru, while Sasuke intends to kill Naruto to awaken his Mangekyou Sharingan.