Teams Kakashi and Guy return home to Konoha. As Kakashi rests in the infirmary, Sakura tells Tsunade about the information Sasori gave her as a reward for defeating him. Sasori had a meeting scheduled with a spy from within Orochimaru's ranks in 10 days

Naruto, Choji and Shikamaru attempt to capture and interrogate Sai, but Sai withdraws after insulting Naruto. Shortly afterward, Ino appears. Concerned that the demon fox could fall into Akatsuki hands, the village elders challenge Tsunade's plan to send Naruto out of the village without the still bedridden Kakashi

Yamato takes temporary leadership of Team Kakashi while Sai insults both Naruto and Sakura. While preparing to set off, Sai receives an envelope from a Root shinobi containing secret orders from Danzo, and Sakura consults with Tsunade. Jiraiya then meets with Tsunade and Yamato in Kakashi's hospital room to brief Yamato on the demon fox within Naruto, detailing the "demon fox's cloak", and revealing a scar he got from Naruto when the fourth tail formed

The new team Kakashi heads out for the Heaven and Earth bridge. Sai, Sakura, and Naruto come to blows after just 5 minutes on the same team due to Sai making fun of Sasuke. Therefore, Yamato decides they need to improve on teamwork and uses Mokuton to create a wooden cage threatening to lock the team up unless they behave

Sakura sees Sai drawing by the river and finds out that Sai has artistic talent but has never given titles to anything he ever drew. Naruto and Sakura begin to realize the reason behind Sai's repulsive personality. After the hot springs, the team heads off to the bridge to meet the spy

Naruto is paired with Sai for the Buddy team of two, over his and Sakura's objections, while Sakura is assigned to support Yamato. Yamato conducts a simulation of the spy meeting with himself as the spy to gauge Naruto and Sai's abilities and teamwork. After Naruto makes a mistake when attacking Yamato, Sai immobilizes him and goes on to capture Yamato alone

Yamato disguises himself as Sasori after creating a wood replica of Hiruko, and goes to meet the spy. The spy turns out to be Orochimaru's right-hand man, Kabuto Yakushi, who reveals the location of Orochimaru's current hideout to Yamato. Orochimaru interrupts the meeting, appearing to attack Kabuto, and while it initially appears that Orochimaru has come after Kabuto, Kabuto attacks Yamato and reveals that he is truly loyal to Orochimaru

Immediately after Yamato signals Naruto and the others out to the bridge where Orochimaru and Kabuto are waiting, Naruto's chakra begins to boil with the chakra of the Nine-Tailed Fox. Slowly, Naruto grows more tails as Orochimaru taunts him and makes him even more angry. Meanwhile, Yamato remembers Jiraiya speaking of how many tails he has seen Naruto grow

Naruto continues to get even more enraged and easily counters Kabuto's attack, flinging him away. Naruto's counter throws Kabuto into Sakura, knocking her unconscious. Orochimaru continues to watch Naruto become more enraged, eventually destroying the Bridge of Heaven and Earth

Naruto, in the four-tailed state, begins attacking Orochimaru with incredible force, devastating the surrounding landscape and preventing Sai and Yamato's wood clone from approaching him. The majority of Orochimaru's attacks prove to be ineffective, but Naruto also fails to kill Orochimaru as he regenerates from any injuries he sustains. Meanwhile, Kabuto advances toward Sakura and Yamato, deducing that Sasori has died

Kabuto comments that Naruto's state is a consequence of his desperation to bring back Sasuke. Sakura begins to cry and approaches Naruto but is injured when his attention turns to her. Yamato uses the mokuton jutsu to bind Naruto before he does any more harm

Yamato uses the first Hokage's chakra to suppress the demon fox's chakra and Naruto returns to normal, but with severe injuries. Sakura begins to heal him, but notes that medical ninjutsu has little effect on his wounds. Orochimaru's sword is revealed to have only pierced one of Sai's clones

Kabuto creates a fake corpse that resembles Sai, containing hidden traps to slow down Yamato's clone after sensing it. Naruto hasn't completely recovered from using the Demon Fox's chakra, and Yamato says that he will be left behind if he cannot keep up. Naruto is determined to finish his mission and not slow the team down

Naruto finally makes sense of the destruction he witnessed around him earlier. Yamato tells Naruto not to rely on the demon because Naruto is strong enough to withstand the demon's terrible chakra. Sai discovers the loss of his book while resting

Sai receives a chilling glare from Sasuke's Sharingan that frightens him. Sai gives Orochimaru a bundle with information about Konoha's ANBU. Yamato gives Sakura and Naruto seeds with his chakra that enables him to track them inside the lair, and reveals that he was able to track Sai because he put a seed in Sai's clothing and food during the visit to the hot springs

Yamato and the team enter Sai's room and confront him while Kabuto makes his way there as well. Sai tells Team Kakashi that not only was he to help with Konoha's destruction but also act as a spy against Orochimaru. Yamato reveals the secret of "Root"- its members were trained like Kirigakure's students in that they had to kill their friends so as to eliminate their emotions

Kabuto fights Team Kakashi and frees Sai. However, Sai, who intends to learn more about his bond with his brother through Naruto's bond with Sasuke, betrays him. Captured, Kabuto gives a vague description of Sasuke's location to the team

As Team Kakashi continues their search for Sasuke, Naruto suddenly collapses due to his previous fight with Orochimaru. As Naruto wakes up, Sai begins to reveal more about his brother, but Orochimaru suddenly attacks them. Sakura and Yamato come to Naruto's aid against Orochimaru, while Sai continues the search

As Team Kakashi continues their search for Sasuke, Sai approaches Sasuke's room and awakens him. Shaken by the image of Sasuke's Sharingan from earlier, Sai attempts to restrain him. A large explosion occurs and Sakura, Naruto and Yamato catch up

Sasuke begins to attack Naruto, but Sai restrains him only for them both to be blown away by Sasuke's Chidori Nagashi. Sakura charges at Sasuke, but Yamato intervenes and winds up being stabbed by Sasuke's unique blade infused with his Chidori. The Nine-Tailed Fox tempts Naruto with its power, but he refuses it

Orochimaru and Kabuto convince Sasuke to withdraw with them, and Naruto weeps over his failure to return Sasuke to the village, but Sakura reassures him that they will bring Sasuke back together. Naruto's team reports to Tsunade about the results of the mission, and Tsunade is greatly angered over Danzo's scheme, particularly his leaking classified information to further it. Sai asks Danzo to allow him to remain with Team Kakashi, and Danzo reluctantly agrees