"The Secret of Jinchūriki" (人柱力の秘密, Jinchūriki no Himitsu) is episode 16 of the Naruto: Shippūden anime.
Team Kakashi and Team Guy are both able to come to the conclusion that the fight they had was nothing more than a distraction to prevent them from rescuing Gaara. Chiyo summons a Mechanical Bird to deliver a message to her brother Ebizō regarding Yūra, the man used as a sacrifice for Itachi. Chiyo explains that for the Akatsuki to use such a technique would mean that they have already begun the extraction. When Sakura asks what she means, Chiyo explains that the tailed beasts were often harnessed for their power by sealing them inside individuals. Those individuals would become host to the beast itself and would be able to keep the beast sealed within them while using the beast's power for themselves. Those individuals, known as jinchūriki, would however die if the beast was extracted from them. Chiyo explains that before Gaara, Sunagakure had two jinchūriki who had Shukaku sealed within them, and they died following the extraction. Sakura is angry that shinobi harnessed the power of the beasts during the war and is about to criticise the jinchūriki who were created, before stopping herself short when she realises that Naruto is a jinchūriki himself. Tearful at the idea of the Akatsuki killing Naruto by extracting the Nine-Tailed Fox out of him, Sakura is about to talk to Naruto when Naruto interrupts, telling them that they should be on the move if they expect to save Gaara.
In Suna, Kankurō stumbles out of bed when he hears that Chiyo has sent a message. He and Baki head to a Suna Council meeting, where it's revealed that Yura was indeed an Akatsuki spy, thus explaining how Sasori and Deidara got into the village undetected. Not wanting to wait for Gaara to return, the council deliberates on choosing a new Kazekage. Kankurō and Baki are appalled, stating that there is nothing that proves that Gaara will not return. A councilman, however, states that Gaara being gone is perhaps best for the village, since most of the village is fearful that the One-Tail Shukaku spirit within Gaara will be unleashed upon them. The council men decide that electing a new Kazekage would bring much needed stability to the village. Kankurō protests, but he is told that once before, the Third Kazekage, the strongest Kazekage Suna ever had, was also kidnapped. Suna had sent many recovery teams to locate him, but they could not even locate his corpse. To make matters worse, neighbouring nations attacked their village when it became known that the Kazekage was no more. Wanting to avoid a war and believing that it is best not to have Gaara in the village, the councilman decides a new Kazekage should be the best course of action. Kankurō tells the Council that while he agrees with their points, he still cannot write off Gaara's fate since Gaara is his little brother.
Kakashi notices that Naruto's pace has slowed down considerably, realising that he must be wiped out from using his Big Ball Rasengan. Kakashi calls for a break, which Chiyo calls a wise decision. Naruto protests, but Kakashi explains that if they were to rest up and then continue, they would reach Gaara much faster than if they continued at their current pace. Kakashi also adds that Naruto would have to be at his full strength in the event that he faces those who kidnapped Gaara. Meanwhile, Pakkun notices that Guy is in pain, due to the toll of opening the sixth gate. Lee asks him if he is okay, but Guy crashes into a tree branch and is knocked out. Neji decides that Guy deserves some rest after using the Morning Peacock, and they decide to take a break as well.
Back at the Akatsuki hideout, the Akatsuki leader commends Itachi and Kisame for stalling the enemy. Sasori believes that he should be praised as well, since it was his two subordinates that were used as sacrifice for the leader's technique. The leader claims that it his technique that did the trick and that his two subordinates should be thankful for the opportunity to serve the Akatsuki, albeit a very brief opportunity. The leader then asks for a status report from Itachi. Itachi states that the Konoha shinobi were none another than Kakashi Hatake, Sakura Haruno and the jinchūriki of the Nine-Tailed Fox, Naruto Uzumaki, along with Suna shinobi Lady Chiyo. Sasori is surprised to hear that his grandmother is on their pursuit. The leader of the Akatsuki then orders Zetsu to find the corpses of the sacrifices and to dispose of them.