Ep. 42: Sword and Shield, Slumbering Weald!

42

After Ash's "Dynamax Band" suddenly starts to glow on its own, he and Goh decide to visit the Galar region and see Professor Magnolia, the leading authority on Dynamax research, but on their way there their train is stopped by a mysterious fog. Leaving the train to chase after a Bunnelby, they get separated in a forest shrouded in thick mist after Goh pursues the Bunnelby on his own. Trying to find each other, they encounter two mysterious Pokémon. Meanwhile, the Galar region is experiencing a phenomenon where Pokémon are Dynamaxing in places where it is normally impossible for them to do so and going on rampages. (Source: Wikipedia)