Riding home atop a train, the Pichu Brothers suddenly find themselves knocked off and flying through the air! They hit a Wynaut on their way down, bringing all three of them to the forest where Pikachu, Totodile, and some more friends are playing in a waterfall and building a campfire. When it starts to rain, the group takes shelter in a water mill—but the water mill starts moving! The next morning, the whole group decides to work together to make sure the Pichu Brothers make their train. Will the two be able to make it home safe?