Ash Ketchum and his friends May, Max, and Brock arrive at a wide crater for a festival centered on the Millennium Comet. This cosmic visitor appears in the night sky for seven days once every thousand years, and its approach awakens the mythical Pokémon Jirachi, who draws energy from the comet to breathe life into the land of Forina where it rests. Yet this cycle is disrupted when a scheming magician named Butler and his girlfriend Diane uncover the stone that seals Jirachi and forcibly remove it from Forina, setting powerful ambitions in motion.
At the festival, May buys a seven-panel charm said to grant a wish for each night the comet shines. While the friends sleep, Butler’s trick takes an unexpected turn when Max hears a voice coming from the rock Diane holds and helps release Jirachi. That night, a hopeful wish for candy is made, but Jirachi’s magic reveals a twist: the candy materializes not from a stall, but is teleported into the festival grounds by the wishful energy.
What follows reveals Butler’s deeper motive: he is a former Team Magma scientist who longs to resurrect the Legendary Pokémon Groudon. His device and thirst for power require a steady energy source, which he believes Jirachi can provide. The sense of looming danger is heightened by the arrival of the Absol, whose presence signals trouble and who joins Jirachi in warning the group and standing against Butler’s plans.
With Diane’s resolve and the Absol’s guidance, the group presses forward, racing Butler’s bus toward Forina as they attempt to shield Jirachi. They dodge traps inside a circus tent and manage to rally the others to follow, while Butler’s Mightyena places a tracking device on the departing vehicle. Though the device falls off during a bumpy journey, the villain tracks their route and closes in on their destination, determined to seize Jirachi once more and fuel his machine.
As the confrontation escalates, Butler’s scheme triggers a catastrophic consequence: the energy harnessed to revive Groudon instead forms a giant artificial monster that begins to drain life from the land, turning Forina into a barren wasteland. The fake Groudon consumes plants and creatures alike, capturing May, Brock, and even Team Rocket who had followed the group. Diane is absorbed by the towering creature, forcing Butler to confront the personal cost of his obsession. With the help of Ash and the others, they create a distraction that allows Jirachi to regroup and push back against the mounting threat.
In the climactic duel, Jirachi reclaims the energy used to power the fake monster and destroys it with a final Doom Desire, then departs to resume its thousand-year slumber. The crisis leaves a mix of relief and quiet wonder in its wake. May, exhilarated by the adventure, forgets to close the last panel of her seven-panel charm, yet she remains confident that her unspoken wish will still come true. As the group prepares to leave Forina, Max hears Jirachi’s voice one last time, a gentle reminder that their friendship will endure beyond distance and time.
