Butler and Diane have been waiting for their baby to arrive. Their wait goes sideways when Arceus whisks them away to a fantastic new world, along with every other human and Pokemon deemed worthy enough. Awakening in a strange new world near a small town called Herd Valley, separated from her husband, Diane must reunite with him before their baby arrives, and possibly do something about the strange egg that she found next to her.

Meanwhile, an evil group takes advantage of the confusion of the Pokemon's appearance to carry out their scheme.