This episode begins at the world of Ninjago.Sensei Wu is walking to the blacksmith shop called the 4 Weapons. Kai is making a sword .He finishs clanging it. Kai dips the sword into some water. When he pulls it out it is crooked. Nya laughs and tells him he did it too quickly. Nya remembers what there father use to tell him. Kai then tells her that he will be a better blacksmith .Sensei Wu enters the 4 Weapons. Sensei Wu accidentally knocks down a helmet. Kai puts down the sword and the hammer. Kai tells Sensei Wu that the shop is calles 4 Weapons not for browsing. Kai picks up a item for a special item for Sensei Wu but he is gone. Kai puts the item down. As the town people are watering the plants a dark cloud starts coming. The Skull Truck and motorbikes come roaring over a hill. Samukai is siting in the truck with Nuckal and a other skeleton. Nuckal tells Samukai he's dying to go fight the towns people. The other skeleton tells him he can't because he's already dead. Samukai and the other skeletons get ready to attack the towns people. The vehicles start driving down the hill. The towns people get ready to attack. Samikai scares the town people. The Skull Truck chases the people away. The vehicles start heading to the 4 Weapons. Kai gets himself ready to fight the skeletons. Krazi gets ready to battle Kai. Kai knocks off Krazi's head. Krazi bites Kai in the leg. Kai kicks Krazi's Head over the 4 Weapons. Chopov and another skeleton chear. Nya hits both of the skeletons. Kai and Nya continue battling skeletons. Nuckal and the other skeleton sneak into the 4 Weapons. Nuckal puts on a helmet. The other skeleton knocks the helmet off with a barrel. Nuckal throws a barrel at the other skeleton. The other skeleton's head spins around. Nuckal and the other skeleton start hiting each other. The other skeleton knocks down the sign and they see the map. Kai sees Samukai. Kai sees that Samukai has four arms and four knives. Samukai knocks Kai down. Samukai stars to spin his knives. Sensei Wu uses Ninjago on Samukai to knock him down. Samukai sees a water tower and gets a plan. Samukai throws his knives at the water tower. The Water Tower's poles break. Sensei Wu saves Kai from geting hit with the water tower. Samukai jumps back onto the Skull Truck. The Other skeleton launchs a skeleton hand from the skull truck to capture Nya. The Skull Truck escapes with Nya. Sensei Wu hits Kai's Helmet with his stick. Kai starts to walk away. Sensei Wu explains that were the skeletons go he can not. Sensei Wu explains the begining of Ninjago and the defeat of Lord Garmadon. Sensei Wu tells Kai he give a map of Ninjago to his father. Sensei Wu tells Kai he has the fire inside and become a spinjitzu master. Sensei Wu knocks Kai down. Kai is seen climbing the rocks to get to the Spinjitzu Dojo. Sensei Wu and Kai walk into the Dojo. Sensei Wu knocks a dragon open and pushes a button. Training Weapons come out of the ground. Kai jumps onto a wooden block. It goes into the ground and shots into the air. Kai flys onto the ground. Sensei Wu tells him to finish the course before he finishs his tea. Sensei Wu tells him that today he falled but he must try again tomorrow. The next day Kai trys the first time but fails. Then the second time he fails. Then the thrid time he fails. Then the fourth time he fails. Then the next day on the first try he finnaly does it. Then Sensei Wu tells him he finnaly did it. He tells him his finnaly test is tomorrow. Sensei Wu goes to bed as secret ninjas walk into the dojo. Kai is shown in the bathroom bushing his teeth. Then Kai pretends to battle Sensei Wu with his toothbursh. The Secret Ninjas jump into the bathroom. Then he sees one of the ninjas right infront of him. Kai pits his toothbrush into one of the ninjas mouth. The ninja spits the toothbrush out and hits one of the other ninjas. The toothbrush flys into one of the ninjas shirt. The ninja starts shaking and buzzing. Kai runs across the hallway. The ninjas jump near him. Kai flys out of the building and lands on the training course. He hits the dragon and actives the course. One of the paper dummys hits a ninja. A spike ball hits another ninja. Kai hits another ninja riding on a punching bag. Kai hits a ninja. A ninja hits Kai. Kai kicks a ninja. Two Ninjas jump at Kai. A Ninja kicks him. Kai steps on a ninjas foot. Then the ninjas pile on Kai. Sensei Wu uses Ninjago to change the ninjas clothing. Jay tells the other ninjas he invints,cooks and makes potery. Cole tells Kai he ain't afraid of anything from this earth. Zane tells Kai he is afraid of dragons. Then, Cole tells him he said from this earth. Jay laughs. Then, Zane fakes a laugh. Sensei Wu tells the ninjas they will take a ride. Kai tells Sensei Wu he is in. It turns out that the ninjas have to pull the carriage. Kai asks where Sensei Wu found the other ninjas. Cole tells he was rock climbing. Jay tells he was trying to fly. Zane tells he was trying to swin in water. They reach the Caves of Despair. Kai is seen jumping across the ground trying to reach the Caves of Despair. Cole,Jay and Zane try to hide from the skeletons. First they hide under a box. Cole,Jay and Zane get Krazi under the box and beats him up. Kai sees Samukai's Tower Hideout. The Ninjas escape on a mover. Nuckal finds a rock shaped like a dount. Two skeletons are seen pushing a mine cart down the rail. The ninjas climb ontop of Samukai's Tower Hideout and look through a hole. They see the map. Zane gets the map. Kai looks at it and flips into the Caves of Despair. The ninjas move the boulder blocking the way to the first weapon. Cole pulls the weapon out of the dragons mouth. When the ninjas walk out of the room they see a room filled with skeletons. The ninjas battle the skeletons and defeat them. The other skeleton tells Nuckal that Kai called him a dummy. Cole turns around and sees the earth dragon. The dragon attacks the ninjas. Kai uses the first weapon to escape. Then, they see Sensei Wu is outside. Cole tells Sensei Wu that Kai used the weapon. Then it shows Samukai talking to Lord Garmadon about how to defeat the ninjas.