"Itachi's Power…!!" (イタチの力…!!, Itachi no Chikara…!!, Viz: The Power of Itachi…!!) is chapter 259 of the original Naruto manga.
Naruto is stuck in Itachi's genjutsu. He tries to free himself by using the Genjutsu Cancel taught to him by Jiraiya, but Itachi neutralises the attempt. He torments Naruto with visions of Sasuke, Sakura, and Gaara and his inability to help any of them. Sakura and Chiyo are able to release him. Kakashi asks for Naruto's help in fighting the actual Itachi.