"Rampage…!!" (暴走…!!, Bōsō…!!) is chapter 293 of the original Naruto manga.
As a fourth tail begins to appear, Naruto, within his subconscious, succumbs to the Nine-Tailed Demon Fox in order to find Sasuke. Yamato wakes up Sakura and, after confirming that she is okay, sends a wood clone after Naruto. As it nears his location the forest explodes and the clone just barely shields itself. It investigates and finds Naruto has reached four tails, a form Jiraiya had warned him about.