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The three Star Cures are the ultimate goal for much of the second half of Mario & Luigi: Bowser's Inside Story. Mario and Luigi first learn about the Star Cures from Dr. Toadley, shortly after a fight with Bowser. Each of the cures are held by a Star Sage, whom the bros. had to convince to retrieve.
Dr. Toadley tells the Bros. that the first vaccine is held by Durmite, who is usually located in Dimble Wood. However, the Mario Bros. had already found and beaten Durmite in Bowser's body. They discover that Durmite is still inside his body, and begin to pursue her. After a battle, Durmite, whose real name turns out to be Wisdurm, relinquishes the first Star Cure on friendly terms after a battle.
The second Star Cure, as it turns out, had come into Bowser's possession before the events of the game, although the sage said it was originally under the possession of Kuzzle. He travels to his Treasure Chamber below his own castle to retrieve it. He is forced to do battle with the Fawful Express for the Star Cure. Mario and Luigi then need to reconstruct Bowser's damaged memory of the combination to the Star Cure's safe. When Bowser opens the safe, however, Private Goomp, Sergeant Guy, and Corporal Paraplonk, shove him inside. Frustrated, Bowser swallows the Star Cure, which ends up in his gut. Starlow notices this and suggests that the Mario Bros. escape with it through a warp pipe.
When all three Star Cures are brought back to Dr. Toadley, he combines them into the Miracle Cure, which cures every Toad that has contracted the blorbs. It also breaks the barriers outside Peach's Castle, allowing the Mario brothers to enter both the castle and the final stretch of the game.
The colors of the Star Cures correspond to the characters who obtained it: red for Mario, green for Luigi (Mario held it, though Luigi was technically the one who knocked down Chakron), and yellow for Bowser.
Names in other languages