Sailing into the fog-ridden forest, with their radar failing on them suddenly and Navi blamed for this course, the Gokai Galleon engages a Zangyack battleship in combat before crashing. Don "Doc" Dogoier panics as he suggests they should leave quickly before they are attacked by the battleship's captain, Action Commander Salamandam, who has been sent to Earth to cause mass volcanic eruptions. The Gokaigers battle Salamandam and the Gormin before the Action Commander uses his tail's eruption-invoking powers to separate Captain Marvelous and Doc from the others. The two then meet the mysterious figure in black, the Red Magician Kai Ozu who points out the Gokai Galleon crew has yet to use the Ranger Keys' true power. Kai tells them that if they follow him without transforming, he will give them information about the Greatest Treasure in the Universe, using his magic and Heavenly Saint Flagel to hinder them along the way. Though Doc is fearful of the obstacles set up against them, Captain Marvelous manages to bravely overcome Kai's magic. Meanwhile, the other Gokaigers assume the forms of Abare Black, Ninja Black, and Go-on Black to take out the Gormin. But when Salamandam arrives, the three take on the forms of Big One, Gao White, and White Swan to drive the Action Commander back, causing him to interfere in Captain Marvelous's literal leap of faith to pass Kai's final test. Though frightened to jump to reach Kai, Doc overcomes his fears in order to save his captain's life from a loose boulder while barely making it to the other side. After explaining to Doc how it was courage that gave him and his family the power to fight Infershia many years ago, Kai reveals that Doc has passed his test to see if his courage can release that same power in the Magiranger Keys. After revealing the Gokai Galleon crew will obtain the Greatest Treasure by mastering the power of all thirty-four Super Sentai, Kai takes his leave as the other Gokaigers arrive when Salamandam emerges again. The Gokaigers proceed, assuming the forms of the Magirangers to fight him. Doc's courage in the face of danger enables them to perform the binding "Magi Magi Go Gokai" spell to hold the Action Commander at bay while they use the Ozu siblings' signature final attacks to defeat Salamandam along with their own Gokai Blast Final Wave attack. When Salamandam and the Zugormin enlarge, Gokaioh is overpowered by the four opponents before the Magiranger Keys react to the situation. Using them, the Gokaigers summon Magi Dragon from within Gokaioh, turning the giant robot into Magi Gokaioh which takes out the Zugormin with its new powers before performing the Gokai Magi Bind finishing attack to destroy Salamandam. With Kai seeing Flagel off to Magitopia, he sees his power is in the right hands as he takes his leave. On the Gokai Galleon, the crew apologizes to Navi for doubting his fortune, before accidentally upsetting the robot parrot once more.
- Continuity Nod: Kai Ozu still has the red streaks in his hair from the ending of Mahou Sentai Magiranger.
- Gravity Is a Harsh Mistress: Don, after blasting a rock that's about to crush Marvelous. Thankfully, Kai is there to lend a hand.
- Monster of the Week: Action Commander Salamandam.