Elsa and her T-Drones dig up a powerful energy crystal, which has the same mineral properties of the Dino Gems. She feeds it to the newly revised and revamped Terrorsaurus II (from "Triassic Triumph"). He fights the four DinoThunder Rangers, and thanks to the crystal, is able to fry their Morphing Energies, leaving them powerless.
Things aren't so well for Tommy, either. Hayley uses his Dino Gem in an experiment to reverse his invisibility, where it overloads, and though he's back to being visible, he's left in a coma. In the hospital, he has a major battle of wills within his fevered mind, facing first his Red Zeo Ranger self, then the White Mighty Morphin' Ranger, followed by the toughest of them all, his old Green Ranger self. Upon resisting defeat, he learns of the true nature of the dream, fighting for his life to prove he's still got a drive to live. He passes the test, and all three of his old selves not only restore him to life, but repair his Black Dino Gem.
Tommy joins the battle against Terrorsaurus II, and with his Super Dino Mode, takes the monster out, restoring his students' powers. The main three Rangers use the Thundersaurus Megazord against the giant Terrorsaurus, and are able to beat him with some Super Dino Mode inspiration.
Oh, and Cassidy & Devin have a bit of a clash when she's eager to go on the air with the story of the Rangers abandoning Reefside.