The Bewildering Forest

is episode 210 of the original Naruto anime.

Synopsis
The boat that Naruto's group is on washes over a waterfall, allowing Naruto, Gantetsu and Todoroki to escape into the forest. Naruto learns from Gantetsu that the forest is the Ninja Dropout hideout, and that only a Ninja Dropout like him can find the way through. Naruto's group defeats one of the Ninja Dropout members, who attacks with a large claw-like machine. Sakura and Lee encounter some orphans who are taking refuge in the forest. It is then revealed that Todoroki intends to kill Gantetsu to avenge his family, and will go so far as to kill Naruto to eliminate a witness to his crime.