Dustin's teammates worry about him when he spends too much time at the track with his new friends Hunter and Blake. He finally comes to his senses, and plays a key part in defeating Lothor's latest monster - the Terra Mole.
Thunder Rangers finally strike, defeating the Wind Rangers with their own Tsunami Cycles and Zords. When Blake is injured protecting Tori, she takes him to Ninja Ops. With their location discovered, the Thunder Rangers infiltrate their headquarters and kidnap Sensei, blaming him for the death of their parents. The Thunder Rangers finally learn that it was actually Lothor who killed their parents, and leave his side.
While infiltrating Lothor's ship, the Thunder Rangers are captured and turned against the Wind Rangers, who already have their hands full battling Toxipod. Choobo sabotages the battle, disabling the Zords, and teleporting the Wind and Thunder Rangers to a deserted island, where they continue their battle, face a resurrected Super Toxipod. The Thunder Rangers are eventually brought back to their senses, and help the Rangers destroy Toxipod and leave the island. They later battle and defeat a banished Choobo, who attacked them to get revenge.
General Trayf captures the Thunder Rangers, and lures the Wind Rangers into his dimension. They defeat him with the Storm Striker and the Storm Megazord, and the Thunder Rangers free themselves from captivity.
After Madtropolis drains the Rangers powers, Cam travels back in time to retrieve a power source that can save them. In the past, he retrieves his mother's green amulet, and a has a hand in the creation of Lothor. Cam returns to present day and destroys Madtropolis as the Green Samurai Ranger. All six Rangers must then unite to defeat an army of five monsters.
An alien being who Shane rescued as a child returns to Earth to give him special powers. He uses these powers to summon the Battlizer Armor, with which he defeats a bounty hunter after the alien - Vexacus.
When an ancient being called Shimazu returns and unleashes powerful monsters on the city, Cam makes a journey to find the Lightning Riff Blaster, which summons the Mighty Mammoth Zord to help the Rangers destroy the monsters.
Zurgane uses the Rangers' own powers against them, as he equips his new Zord with data from the Power Spheres. The Rangers destroy it by combining the Hurricane Megazord with the Mighty Mammoth and all of their Power Spheres. Zurgane is then destroyed by the scheming Vexacus.
Using gem of soul fragments stashed away by Hunter, Cam infiltrates Lothor's ship to free the captured ninja students. When Cam is needed back on Earth, and is found by Lothor, he is forced to give up his rescue mission.
Lothor opens the Abyss of Evil, bringing back all of his past monsters and generals. The Rangers defeat them with the help of the freed ninja students. After losing their powers, the Wind Rangers defeat Lothor for good by using their own inner ninja powers.