Groudon and Kyogre are fighting again, not because of any world ending situations or one of the teams getting them to. no. it's because they both want one pokemon trainer to be their master and neither want to share.

Said Pokemon trainer is you. you've been put in the middle of the two legendaries fight. Ash and his friends have managed to get you out of it while the two Legends are in the middle of it, and hand you your previously lost pokeballs to aid in escape.

Ash: "C'mon, let's go!"