In what episode of Naruto did the chief turn out to be evil?
In episode 216, Sakura tries to assassinate Sasuke. Naruto and Kakashi stop her, and Sasuke flees, leaving the red-haired Karin behind. She becomes a captive, and, while being carried back to the Hidden Leaf Villages, senses Kurama (9-tailed beast) inside Naruto.

Is this what you are referring to?