Heading to the next island, Alexa informs Ash & Co. that there are rumours of a hidden treasure on a nearby uninhabited island. Ash & co. decide to investigate this to try and find the treasure, helping Alexa to solve the mystery she learned when doing a report years before. However, Team Rocket have heard about the treasure as well and head there, and to top it off, the wild Pokémon on the island are intent on protecting it. Will Ash & Co. find it?

Arriving on the next island, Ash & co. learn that it's the time of the year for the Woodate's Comet showing, which only appears once every 10 years, so they go to the top of a mountain to observe it. It is said that when the comet passes, the Pokémon in the area start acting strangely. When travelling up the mountai, they discover Woodate's battlefield amongst the ruins, but soon find that Team Rocket have a plan set. Will they managed to stop Team Rocket in time to see the comet?