New episode title(s) has/have been added to the database. Title: お宝の謎！ 無人島アドベンチャー！！/Otakara no nazo! Mujintō adventure!!. Please comment below! Thanks, your friendly PM.Net AnimeBot

Satoshi and friends have come to an uninhabited island in search of a Pokémon treasure said to be hidden there by pirates of legend. They head onwards, using a map Pansy brought as their only clue... and then suddenly, they're attacked by Pokémon...!?

Summary:
As Satoshi and friends visit Palm Island, Pansy tells them about a 'legendary treasure related to Pokémon' said to be hidden on a nearby uninhabited island. The groups heads to the island and embark on a treasure hunt, set on solving the mystery behind the 'secret code that leads to a treasure' the Pokémon reporter Pansy discovered when she went to a pirate museum to do an article.

The Rocket Gang, who heard of the treasure in that same way, head to the island as well... but as Satoshi and friends move thrugh the island, they are attacked by one Pokémon after the other. Will they manage to safely get the treasure?

Voice Cast:
Rica Matsumoto: Satoshi
Ikue Ohtani: Pikachu
Mamoru Miyano: Dent
Aoi Yuki: Iris
Minami Tsuda: Kibago
Megumi Hayashibara: Musashi
Shinichiro Miki: Kojiro
Inuko Inuyama: Nyarth
Aya Endo: Pansy
Chika Fujimura: Erikiteru
Misato Fukuen: Mijumaru
Wasabi Mizuta: Chaoboo
Kensuke Sato: Kairyu
Mika Kanai: Deathmas
Kiyotaka Furushima: Koromori
Tsuguo Mogami: Dirteng
Unsho Ishizuka: Narration

This time a Geocaching episode! With a mystery geocache! Oh wait. Mystery caches just suck. :/ And it is actually just a treasure, not really a Geocache :P But it could be implemented as a real Geocache with a bit of effort.

Before any treasure hunt really begins, Rocket Gang enter the scene as cosplay freaks again. And here when I expect them to utter a pile of Tauros droppings again, they say something that really gets my attention. A reference to Gold, Silver, Ruby, Sapphire, Emerald, Diamond and Pearl. Well played, Rocket Gang, well played.

One random whirlpool later:
A completely WTF moment was when Rocket Gang's failed attempt to resurface with a submarine sends an old gigantic pirate ship with Satoshi inside almost flying and then the ship just... sinks. On a beach.

Then some puzzle-solving begins. I guess this would get a difficulty rating of 3 if it was a Geocache. But after solving it, the bricks just.. fall down to the ground? What kind of technology is that?

Then some Eevee-saving occurs, some battles here and there, some water here and there and suddenly treasure.

I was positively surprised by what the treasure actually was. If I found this in a Pokemon game, I would be very happy :)
Just the logbook was missing there.

However, Rocket Gang is way too persistent in this episode. They get blasted off by Ninetales and then they just suddenly return to the same hill again after Ninetales is beaten and mercylessly thrown away by Satoshi's Charizard. (That was a bit brutal by the way)
They return only to call out completely exhausted Pokemon, return them back to their Poke-balls right away and get blasted off by Pikachu's Thunderbolt O.o Seriously, what the hell is this?

My rating:
Not a bad episode, though it is more or less a filler with a bit of mystery to it, but without any greater amount of originality. I like treasure-hunting episodes, but I think I have seen better. The best thing about this hunt was the treasure itself and the small surprise evolution at the end. Other then that, it is quite an average episode.
I give it 7