Ash, Misty and Brock have reached the famous Ruins of Alph. Summoned there by a note from Professor Oak they join him and an old student of his, Foster in a facility for studying Pokémon fossils. Foster has made an amazing discovery, live prehistoric Water-type Pokémon thought to be extinct for thousands of years! Does their appearance have anything to do with the interrupted water flow from a nearby reservoir? Watch as our heroes find out what's fishy with the freshwater!