"At the Northern Hideout" (北アジトにて, Kita Ajito nite) is chapter 349 of the original Naruto manga.
Karin warns Sasuke about Jūgo, but he is not concerned. Knowing little about Jūgo, Suigetsu asks what the problem is. Karin explains that Jūgo willingly became a prisoner of Orochimaru in order to find a cure for his murderous impulses. By experimenting on Jūgo, Orochimaru's Juinjutsu were created. With Orochimaru now gone, recipients of one of these cursed seals run rampant at the base where Jūgo is held. One escapes and finds Sasuke and the others approaching the base. He attacks them, but Sasuke quickly cuts him down.