Watch Naruto Episode 18

This Naruto episode is entitled "The Weapons Known as Shinobi"

Kakashi prepares to stop Zabuza once and for all, but Haku sacrifices his own life to spare Zabuza. Now Zabuza is ready for another round, only Kakashi isn’t playing around this time. Failing miserably, Zabuza is confronted by his employer, who has decided to take matters into his own hands.