It opens with a lab escape and a Mewtwo that is not the one you grew up with, and that swap is the whole point. The Prologue to Awakening short did the setup work, giving this Mewtwo its own history and grief before it ever shares a frame with Satoshi, so by the time it squares off with the Genesect Army you already know what it is protecting. Then comes the transformation into Mega Mewtwo Y, the first Mega Evolution the anime ever put on screen, dropped into a Pokemon movie a full generation before the games caught up. The Genesect themselves are the good part of the bad guy math: five ancient bugs revived and bolted with Drives, led by a red one that is not evil so much as furious and lost, tearing apart Pokemon Hills looking for a nest that stopped existing 300 million years ago. It is a plot-first film where the creature just wants to go home.

After three hundred million years, the snowy mountains where the ancient Genesect once lived can no longer support them, so a few survivors set out to find a new home. Led by a red, Shiny Genesect and joined by the Legendary Pokémon Mewtwo, they reach New Tork City and claim a park in the city center, pushing out other Pokémon and endangering the residents. The Genesect distrust people, and their leader rejects Mewtwo's help. The two clash in a battle that threatens to level the city, and Satoshi and his friends must stop them and make peace between the feuding Pokémon. The 16th Pokémon movie mixes action, adventure, comedy and fantasy.