The Powerful Helper

is episode 200 of the original Naruto anime.

Synopsis
Konoha begins taking action to disarm the traps without Gennō finding out. The research then concludes that Gennō set the traps 30 years ago, as part of a mission for the Kagerō Village, which was destroyed by another village shortly after he completed his mission, resulting in his son's death. Naruto comes to terms with the fact that the old man he befriended attempted to destroy the village, and finds a lead that Gennō is in the mountains. Meanwhile, Team Asuma investigate the events of thirty years prior.