There are three checkpoints on the way from Shinano province to Owari province. One of them Ogase, was where Gorōta was discovered as a spy. Shintarō decides it would be better to go around over the mountains and avoid the checkpoints but they need a guide. Tonbei goes in disguise to Ogase to contact Seihachi, the spy samurai there who owns a small medicine shop. At the checkpoint, Gensai is sitting with the guards, giving the nod or not to those passing through. Tonbei passes through safely despite Gensai giving him a hard stare and reaches Seihachi, unaware that the identity of the spy samurai is known to the Black Ninja as it had been discovered by Ghost Koroku of Koga. Seihachi says the hunter, Sakuzō who lives on Eagle Mountain will guide them. Kazeba comes to warn them and offers to show them another way but she is not believed. Shintarō will go over the mountain while Tonbei goes through the checkpoint. This time Gensai identifies him and orders him killed. He has a narrow escape as Kazeba rescues him. She tells him Gensai knew who he was all along but was using him to lure Shintarō into a trap. Sakuzō attacks Shintarō in his hut, is bested and runs out. Seihachi arrives and says he has killed Sakuzō and will guide him. Shintarō notices there is no blood on his sword then Tonbei and Kazeba turn up saying Seihachi and Sakuzō are both Koroku in disguise. Koroku is killed in a fight , leaving them free to cross the mountain.
