Casey Shield, a hacker who invented the Dynamax Simulator, and Henry Sword, a boy who repairs gear for Pokémon, both dream of entering the Galar region's Gym battles. For Casey, it's a chance to reunite with her lost Pokémon. For Henry, it's an opportunity to search for the legendary Rusted Sword and Rusted Shield.

Even with Legendary Pokémon Zacian and Zamazenta helping them in the fight against the Gigantic Pokémon Eternatus, Henry, Casey, and their friends lose the battle and must retreat. When Eternatus disappears, it takes Henry, the Rusted Sword, and the Rusted Shield along for the ride!

Can the team find and save Henry?!