After the battle of Castle Oblivion, Sora has chosen to regain his old memories and has been put to sleep until he is whole once again. With his absence, dark forces are able to do as they please with their only true opposition missing in action. The strength of the Heartless continues to grow rapidly by each day with different puppet masters pulling the strings. In the process of returning Sora's memories, his own heart is threatened by a darkness that will consume him if nothing is done to stop it. Pipsqueak and his companions must hold off the ever growing threat that not only grows in the Realm of Light, but the darkness that is festering is Sora's heart as well. Will they be able to accomplish the daunting mission given to them? Or will they all be consumed by the darkness as well?