The Weapons Known as Shinobi

A weapon chooses its moment to be a person. Sensing Zabuza about to die under Kakashi's summoned hounds and crackling Lightning Blade, Haku abandons his fight, body-flickers across the bridge, and takes the assassination technique through the chest — a shield with a heartbeat. Kakashi's hand exits the back of a boy he didn't intend to kill. Naruto, arriving seconds later, finds the enemy who spared him dead in the service of a man who calls him a tool. Zabuza's response: 'he was just a tool.' Gato's mercenaries land at the bridge's end.