The episode opens with Kai and Nya working in thier family blacksmith shop, Four Weapons, after their father's recent death. The two are approached by Sensei Wu, who shows disdain for the weapons they make, saying they are useless in the art os stealth, and are no weapons for a Ninja. Kai drives him off, who in turn disappears when Kai turns his back. Moments later, a dark cloud appears over the village, catching the eye of local villages and farmers. On the edge of the hill, the Skull Truck appers along with motorcycles, all of which are driven by skeletons. The skeletons began their attack, causing the villagers to flee. Kai fashions hand-crafted samurai armor, a helmet, and a sword. Then, Nya joins his brother in battle. Soon after, Kai is almost killed by Samukai. Nya is grabbed by a skull grappling hook and kidnapped under orders of Lord Garmadon. Wu tells Kai the story of Ninjago. Wu asks Kai to join him as a ninja. Kai refuses, until understanding he won't stand a chance without Spinjitzu. Kai trains in Wu's Monastery. After a few days, Kai completes his training. When preparing for bed, he is attacking by three ninjas.
- Kai and Nya's Father (Mentioned)
- Lord Garmadon (Mentioned)
- Sensei Wu and Lord Garmadon's Father (Flashback)