Continuing from Episode II: The Samurai Called Jack, Jack and the archaeologists begin to plan for the invasion coming the next day. Jack comes up with a plan to use the digging and transportation equipment to set up a layer or traps to thin out the army of Beetle Drones. While the archaeologists set up the traps, Jack looks for items that can be used as weapons. He finds out that the very jewels Aku has been forcing the archaeologists to dig can be used as weapons and makes them into spears and arrows for a bow he made. With the traps set, the archaeologists create an armor for Jack as he tames one of the animals to use as a steed. Soon, everything is set up and Jack waits for the morning.
As the sun rose, the beetle drones had entered the valley and Jack headed out to face them. When Jack caught sight of the coming hordes, he activated the first trap, catapults made from digging machines. He fired his arrows at each of the start buttons of the machines, causing them to fire the stones into the middle of the army, destroying several Beetle Drones. Jack then activated the second trap, exploding barrels by firing arrows at flint on top of the barrels, creating several explosions and destroying more Drones.
Jack and his steed then rush towards the Drones to engage in combat. Jack fires the last few arrows as his steed rams through the Drones. Jack begins using the spears he made and manages to destroy a few more drones before being knocked off his steed. Left alone on the battlefield, Jack draws his sword and begins fighting, but is overwhelmed and stripped of his armor. Jack managed to get away from the Drones and lead them to the third trap, loose rock pillars. Jack quickly knocked them over, causing a rock slide that destroyed more drones as well as creating a walkway to the fourth trap, spaceships made into flamethrowers. Jack ignited them and destroyed several more drones before they ran out of fuel. Jack began to lead the Drones to their last trap, a spike pit made using the jewels. Jack jumped over the pit, leading the Drones into falling into the pit, drastically cutting their numbers. Unfortunately, it didn't get enough of them as Jack was still immensely outnumbered and all out of traps.
Left without any other strategy at his disposal, Jack could fight with only his sword. The drones kept coming, injuring Jack while he destroyed as many as he could. Eventually, Jack became enraged and got covered in the oil of the drones he destroyed (while in slow motion). Covered from head to toe in the black oil, Jack stared at the remaining drones, who had become terrified at the sight of the samurai covered in the oil of their fallen brethren and slowly started to step away. Jack said "No. There is no escape" and began to destroy the last few drones until there were no more. With the drones destroyed, the archaeologists are freed and could continue their studies of their past. They offer Jack a chance to travel with them, but he declines and continues his journey to right Aku's wrongs and eventually finding a time portal.
Aku, who had been watching the battle the whole time, promises Jack (and refer him by name for the first time) that he will destroy him and that the time and place will be his choosing.