The Mystery of Tobi

Deep in the woods the Eight Man Squad cannot lay a finger on Tobi. Naruto's Rasengan, Yamato binding him with Wood Release, and Shino's Insect Sphere all phase harmlessly through the masked man. Kakashi bares his Sharingan but holds back as Zetsu appears with startling news: Sasuke has killed Itachi. The revelation stuns the group, and Tobi instantly abandons his shrill, buffoonish manner for an icy tone, saying he will deal with them another time. Before he and Zetsu leave for the Uchiha Hideout to collect the bodies, Tobi fixes his gaze on Kakashi, who realizes with alarm that Tobi too wields the Sharingan.

Among the hideout's ruins, Tobi asks whether Zetsu captured a recording of the fight to study later, and the pair gather the fallen Uchiha before fleeing. Zetsu also breaks up the clash between Kisame and Suigetsu, relaying Sasuke's victory and inviting Hebi eastward, though Kisame elects to walk away from the Akatsuki now that Itachi is gone. Guided by Hinata's Byakugan, the Eight Man Squad presses toward the hideout, only to be stopped by Itachi's lingering Amaterasu until Yamato carves a safe route with Earth Flow Divide. Reaching the wreckage, they find Sasuke already spirited away, and Naruto breaks down over never managing to catch up to him.

At the Akatsuki base, Tobi tells Sasuke he survived the fall of the Uchiha Clan and lifts part of his mask to reveal his Sharingan. Sasuke's left eye suddenly awakens into Itachi's Mangekyo and sets Tobi ablaze with Amaterasu; he escapes and returns to explain that Itachi had implanted the flame in Sasuke, rigged to erupt on eye contact with his Sharingan. When Sasuke asks why his brother would do such a thing, Tobi answers that he knows far more about Itachi than Sasuke does, including that everything Itachi did was meant to protect him.

Tobi is revealed to possess the Sharingan and drops his goofy persona upon learning of Itachi's death. Kisame quits the Akatsuki, and the Eight Man Squad finds Sasuke gone from the hideout. Sasuke unknowingly triggers Itachi's implanted Amaterasu against Tobi, who begins hinting that Itachi's actions were always in Sasuke's protection.

The episode adapts several chapters of the manga and falls within the Fated Battle Between Brothers arc, airing under the opening theme Sign.