Each Star is a specific world. Should a star stop shining , that would mean that particular world has disappeared from existence , most likely from destruction by the Heartless.
Donald,
Sorry to rush off without sayin' goodbye, but there's big trouble brewin'.
Not sure why, but the stars have been blinkin' out, one by one. And that means disaster can't be far behind. I hate to leave you all but I've gotta go check into it. There's someone with a "key"—the key to our survival. So I need you and Goofy to find him, and stick with him. Got it ? We need that key or we're doomed ! So go to Traverse Town and find Leon. He'll point you in the right direction.
P.S. Would ya apologize to Minnie for me ? Thanks, pal.
Signed
- Mickey
When Donald enters the Disney Castle Throne Room to give Mickey his morning greeting, he finds only Pluto, with the first letter. He rushes to show it to Goofy, while trying unsuccessfully to keep it hidden from Minnie and Daisy. With the help of Chip and Dale, Donald and Goofy are sent to Traverse Town to talk to Leon.
Per Mickey's orders , they join up with him. To be on a lookout for a mysterious key.
Many stars had disappeared. In Mickey's first letter to Donald, Mickey mentions the fact that the stars have been disappearing, one by one, and that he left to find the cause. When Donald and Goofy first arrived at Traverse Town, they discovered a star corresponding Destiny Islands fade out of existence.
The king of Leon's home world, a man named Ansem, is said to have studied the Heartless. Donald and Goofy are approached by Leon's ally Aerith, who also tells them what they may be looking for a keyblade.
A keyblade has the power to open or close any lock or door be it to a physical object, to the heart of a person or world, or to a gate or pathway between worlds. For objects like treasure chests, this merely requires tapping the chest, while for more magical locks, the Keyblade generally operates by emitting a bright, thin beam of light from its tip, or by being thrust directly into the keyhole or person's chest. It plays an important role in the battle between darkness and light.
Prior to the release of the Heartless, the worlds were surrounded by barriers to prevent outside interference, making it impossible for different worlds to have contact. However, the arrival of the Heartless caused the barriers between the worlds to crumble and disappear, and some worlds were consumed by the eldritch horde. Gummi Blocks are pieces of these broken barriers.
Those who travel between worlds are advised to avoid meddling in the affairs of other worlds and informing their inhabitants of the existence of other worlds. In order to maintain a balance of separation.
Donald and Goofy are again traveling in the Lanes between using their gummi ship after searching many worlds.
" some help that is , now how are we supposed to find this key we had been searching for nearly 12 years. "
" maybe its in someplace where we have not looked " pointing to a star named Eos on their map
Donald and Goofy then steer their gummi ship toward the star...
" O'er rotted Soil, under blighted Sky, A dread Plague the Wicked has wrought. In the Light of the Gods, Sword-Sworn at his Side, 'Gainst the Dark the King's Battle is fought. From the Heavens high, to the Blessed below, Shines the Beam of a Peace long besought. Long live thy Line and these Stones divine, For the Night When All comes to Naught. "
On the surface of Eos
The Kingsglaive are in the midst of a battle to protect Lucis's borders from both beasts and daemons, and the attacks of Niflheim's magitek armies. During one such operation, Nyx defies his orders to withdraw to rescue his friend Libertus, whose leg was trapped under a rock, from a giant daemon captured by Niflheim and sent to the Lucian front.
In the wake of the operation, Nyx is reassigned as a city guard by the Kingsglaive captain and Nyx's superior officer, Titus Drautos, where he experiences first-hand the hostility Insomnia residents feel towards the Kingsglaive. The Kingsglaive themselves feel this hostility, although Nyx doesn't let it bother him due to his faith in Regis.
The battle leaves Lucian forces in a weakened position. Ardyn Izunia, chancellor of Niflheim, arrives and offers terms for peace between Lucis and Niflheim—Lucis must surrender all territories beyond Insomnia to Niflheim, and Regis's son Noctis is to marry Lunafreya. This causes consternation and division among the Lucian Council, but Regis agrees due to his accelerated aging preventing him from commanding the greater magics of the hereditary Ring of the Lucii. He deems himself unable to fuel the Crystal's magical barrier for much longer than a few remaining years, as maintaining the New Wall has been draining his life-force and causing his premature aging. Regis's acceptance of the peace terms causes dissension among the Kingsglaive, who feel Regis is abandoning their families and homes that extend beyond the Crown City in other parts of Lucis.
During this period, Lunafreya attempts to leave for Lucis incognito to pursue her own goals concerning Regis and Noctis, but she is prevented by Ravus. Despite her telling him that Niflheim is using him as their "lap dog", Ravus continues to blame Regis for the death of his mother. Parallel to this, Kingsglaive member Crowe is sent on a mission beyond Lucis to help escort Lunafreya and present her with a hairpin, and is killed by an unknown assassin. Her death and the circumstances surrounding it enrage Libertus and he leaves the Kingsglaive to join a group of Lucian rebels, giving them information about the workings of the capital's security, as he blames the king for Crowe's death, who he cared for as a little sister.
At a party at Caelum Via dedicated to the signing of the peace treaty, attended by both Regis and Niflheim's emperor Iedolas Aldercapt, Lunafreya meets Nyx. She learns of Crowe's death and receives the hairpin. While praying for Noctis's continued safety, Lunafreya is abducted by Glauca, who confirms her suspicions that the treaty is a ruse. Nyx discovers this and finds that Niflheim has stationed airships outside Insomnia. Regis agrees to deploy the glaive, although their leader, Drautos, has disappeared.
While Nyx rescues Lunafreya after having realized the hairpin is a tracer, many of the Kingsglaive turn on him and the other loyal members. All but Nyx, Lunafreya, and a few of the rebel traitors and the rebel leader, Luche Lazarus, are killed in the ensuing battle with an Ultros daemon commanded by Niflheim.
At the treaty signing, Regis prepares to either capture or kill Iedolas. The Niflheim delegation springs a surprise attack, leading to a temporary stand-off. Using information from the Lucian rebels, Niflheim soldiers infiltrate the Crystal's sanctuary, destroying the apparatus that powers the city's shield. This allows Niflheim to attack in strength, leading to the swarming and death of most of the Lucian Council once magitek soldiers infiltrate the room along with General Glauca.
As Lunafreya and Nyx head for the Royal Citadel, Regis and his former protector Clarus Amicitia fight together against Glauca and the magitek forces. Glauca kills the remaining council members, including Clarus, leaving Regis alone. Just as Lunafreya and Nyx arrive, Glauca attacks Regis, cutting the Ring of the Lucii from his hand. Ravus, having wished for Lucis's downfall since his childhood, puts on the Ring to access its power: the Ring violently rejects him, severely burning his arm before he can get it off. Taking the Ring, Lunafreya and Nyx lead the wounded Regis away with Glauca in pursuit. Despite Nyx's anger at Regis for seemingly allowing the destruction of Insomnia to protect his son, as he knew what the empire was planning, he agrees to get both Lunafreya and the Ring out of the capital.
Lunafreya tries to bring Regis with them, but, his strength waning, he commands them to leave without him. Staying behind, Regis raises a barrier to protect Lunafreya and Nyx before he makes his final stand and struggles to defeat Glauca, holding him off with lightning magic before being overpowered and killed. The surviving members of the Kingsglaive, and all those close to King Regis, lose their magical abilities, rendering them powerless against Niflheim's attack. Iedolas and Ardyn steal the Crystal from the Citadel, fleeing the besieged city with it. In the midst of the chaos, Libertus learns that the rebels—himself included—were used as the empire's pawns and will now be blamed for the fall of Insomnia as terrorists.
Lunafreya and Nyx are summoned to the city plaza by a call from Drautos: once there, the two are cornered by Lazarus. Severely wounding Nyx, he reveals that he had killed Crowe, and that Niflheim promised the Kingsglaive and their families Insomnia as their new home if they cooperated. Lazarus almost obtains the Ring, but Lunafreya tricks him into putting it on, killing him.
Drautos appears and is attacked by a repentant Libertus, who has learned of the rebels' role in Lucis's fall, and Drautos's true identity. It is revealed that Drautos is Glauca, and his indomitable strength means Nyx is powerless without access to magic. Glauca is about to kill the three when Nyx puts on the Ring; he finds himself in an otherworldly realm, where he demands the spirits of the past kings of Lucis to appear. They denounce him as unworthy of bearing the Ring's power, not being of royal blood and unwilling to choose between Libertus's or Lunafreya's life as the demanded sacrifice.
They relent due to King Regis's spirit's intervention, and when they realize that Niflheim will otherwise capture the Ring just as they did the Crystal. Nyx is granted use of its power when he reveals he fights so that others will have a better future, with the cost being his life once the sun rises.
His power restored and enhanced, Nyx fends off Glauca. He returns the Ring to Lunafreya, entrusting her to Libertus and telling them to flee. Nyx and Glauca engage in a titanic battle throughout Insomnia, with both the city's statues animated by the Ring's power—the "Old Wall"— and the daemons used by Niflheim clashing around them. From an airship above, Iedolas and Ardyn watch, with Ardyn being intrigued by the Old Wall's power. Iedolas simply orders them to leave the ruined city and destroy the daemons now the Crystal is theirs. Though following his orders, Ardyn decries the "waste" of the great city and powerful daemons being needlessly destroyed.
The fight ends with Nyx fatally wounding Glauca by stabbing him in the chest. Nyx dies shortly after as payment for using the Ring's power as his skin has become like ash with his veins burning, and he starts to disintegrate. Libertus—now one of the few surviving members of the Kingsglaive—decides to stay behind at Luna's behest, while Lunafreya leaves with the ring to find Noctis.