Shaymin, the peaceful Gratitude Pokemon, lives happily in forests and fields of flowers. But one day Shaymin is accidentally drawn into a battle between the Legendary Pokemon Giratina and Dialga. Whisked away far from home, Shaymin is found by Ash, Dawn and Brock, who soon discover that this new Pokemon is full of surprises! Of course Team Rocket wants to get their hands on Shaymin, and so does a mysterious man named Zero. Even Giratina is in hot pursuit of this little Pokemon--and just what do Giratina and Shaymin have to do with the dimension known as the Reverse World?