Ash, Pikachu and his friends try and stop a pair of thieves hiding out in the canals and alleyways of Alto Mare, the age-old water capital. Joining the adventure are two new legendary Pokémon, a pair of siblings named Latias and Latios, who serve as peacekeepers and protectors of the Soul Dew - a priceless treasure with a mysterious power.

The lives of young Yugi Muto and his friends Joey, Tristan and Téa are forever changed when a fantasy card game becomes their reality.