Naruto, Vol. 7 by Masashi Kishimoto

Deep within the Forest of Death, Naruto, Sasuke and Sakura are still reeling from Orochimaru's attack...and now they must battle his minions, the mysterious Sound Ninja. And as Sasuke struggles with the strange force growing inside him, spreading like an infection from the curse-mark Orochimaru burned into his neck, time is running out for the student ninja to collect the scrolls they need to pass the Chûnin Exams!