Too Late for Help

is episode 164 of the original Naruto anime.

Synopsis
Mōsō states the mission is over. Naruto, however, is skeptical, and investigates where he and his companions fought the Cursed Warrior. He finds a secret passage to the feudal lord's mansion, but is caught. When Chishima goes to warn Mōsō about Naruto investigating, he accidentally sees Mōsō meeting with Watari ninja. Chishima tries to escape to inform the others about this development, but is pursued and injured by the Watari ninja. The Cursed Warrior arrives in Naruto's cell, but turns out to be Sagi in the Cursed Warrior's armour. Sagi decides that because Naruto trespassed, he will be sentenced to death.