This is likely to be a very large fanfic centring around the character Melody from Pokémon 2000 The Movie.
What happened in Pokémon 2000?
Disturb not the harmony of Fire, Ice, or Lightning, lest these Titans wreak destruction upon the world in which they clash. Though the water’s Great Guardian shall arise to quell the fighting, alone its song will fail. Thus the Earth shall turn to ash. O, Chosen One, into thine hands bring together all three. Their treasures combined, tame the beast of the sea.
This is an introduction to the legendary three birds, Articuno, Zapdos and Moltres, around which the plot revolves, introducing the theme of a delicate balance between the forces of nature (a common theme throughout the Pokémon series), embodied by the very Pokémon who represent them. The idea of the legend is that should the balance of power between these three birds be destroyed, chaos would ensue, prompting the “Great Guardian” Lugia to rise from the depths of the sea to attempt to end the senseless destruction, yet only with the help of a “Chosen One” destined to save the world.
It is the ambition of a certain collector of Pokémon items to add Lugia to his collection by disrupting the balance of nature and summoning Lugia, believing himself able to tame the beast once he has brought together all three legendary birds. Though the man’s name is not revealed in the movie, “Lawrence III” is given in pre-release sources and the name Gelardan is revealed in closed captioning.
Lawrence uses a technologically advanced airship to launch an ice attack on Fire Island, the home of Moltres, in order to drive it out. The legendary bird fights back but is swiftly captured.
Meanwhile, as Ash and company travel throughout the Orange Islands on board a boat captained by Maren, a storm suddenly brews up, sending them off course. Soon after, they end up beached on Shamouti Island, coincidentally arriving during an annual festival which honors the aforementioned legendary birds. Ash agrees to play the role of the festival’s ceremonial “Chosen One”, and is faced with the task of retrieving three elemental orbs from the three nearby islands (and residences of Articuno, Zapdos and Moltres), and return them to a shrine, representing the uniting of the powers of Fire, Ice and Lightning.
In Pallet Town, the storm that Ash and company encountered proves not to be an isolated incident, as the town too experiences extreme and erratic weather patterns (brief yet heavy rain, snow during the middle of summer and even the Aurora). Ash’s mother and Professor Oak notice that the Pokémon are behaving strangely as well (as they are more in sync with the forces of nature). Sensing impending danger they, along with Professor Ivy, set forth for the Orange Islands, to which the Pokémon are headed as well, as it seems to be the source of these disturbances.
Back in the Orange Islands, Ash and Maren head for the first orb on Fire Island, despite the advice of the festival maiden Melody and the horrendous weather outside. Blaming herself for what could happen to Ash, given the terrible situation, Melody (along with Misty and Tracey) takes off after him. After Ash obtains the first orb, the two groups meet, along with Team Rocket, who had sneaked aboard Melody’s boat. Zapdos then suddenly appears, having claimed Fire Island as its own owing to the disappearance of Moltres. Its reign is short lived, as Lawrence’s airship descends from the clouds and captures Zapdos. However, everyone else in the vicinity is also captured and brought aboard.
As this occurs, Professor Oak, en route to the Orange Islands, concludes that because the basic elemental forces of fire, ice and lightning have been disrupted, there have been great disturbances in the ocean’s underwater currents (home of Lugia), and that if order is not restored soon these disturbances could end up flooding the entire earth.
On his airship, Lawrence III greets his prisoners and explains his plan, much to the disgust of the rest of the characters. Using her prior knowledge of the legend, and having observed Lawrence III’s plan, Melody comes to the same conclusion Professor Oak has. Meanwhile, Articuno appears to fight Lawrence III and his airship. Articuno manages to avoid getting captured, and Articuno damages the airship heavily. The group are able to, using their Pokémon, free themselves and release Moltres, who then frees Zapdos. Zapdos and Moltres then fight each other, destroying the already damaged airship and causing it to crash on Lightning Island. Ash collects the second orb as Articuno, Zapdos, and Moltres battle each other. The fight, which threatens property and lives, is halted by Lugia, who rises from his slumber to help try to restore peace. Lugia then takes Ash and company to the island on which the three orbs must be placed, a task that holds the fate of the world in the balance. Lugia attempts to stop the fighting between Articuno, Zapdos, and Moltres, but is overwhelmed.
While watching the fight, the Slowking that guards the shrine tells the main characters that Ash is truly the Chosen One that legends had foretold (“The world shall turn to Ash” is a reference to Ash the person, although it was previously misinterpreted by most. Ash, upon hearing this, jokes he wished his mother had named him Bob.) However, Ash must still obtain the third orb from Ice Island, with the three birds standing between them and their goal. Encouraged by Charizard, Squirtle, and Bulbasaur, Ash and Pikachu, with the help of Team Rocket and Lugia, manage to reach Ice Island and obtain the third orb. Lugia is suddenly captured by the collector, and, in an attempt to break free from its restraints, Ash is tossed into the water between the two islands and almost drowns, but not before an angry Lugia fires an Aeroblast at the collector’s ship, reducing it to rubble. After he is rescued by Misty and Tracey, Ash manages to bring the third orb to the shrine, and Melody plays Lugia’s Song, which with the power of the orbs, restores harmony to the forces of nature.
With the entire ordeal over, Ash and his friends leave Shamouti Island. At the end of the movie, Team Rocket are upset that they did something good that no one saw, but Slowking breaks the fourth wall by saying a lot of people were watching, and points to the screen, and seemingly out to the viewer(s).