Pokémon Super Mystery Dungeon: Echoes of Yesterday

There exist many different organizations in the Pokémon World, one of these being the Expedition Society from Lively Town. They go on expeditions all around the world, scouting up unknown places, filling the World Map and helping Pokémon in need.
One day, a certain rumor reaches Ampharos's ears, and soon thereafter the whole group embarks on an expedition to the Grass Continent. Archen, their newest member, is both excited and nervous.
What challenges will be waiting there? Will they have what it takes to solve the mystery? They will have to work with new and old friends.
Join the members of the Expedition Society on this little adventure taking place before the events of Super Mystery Dungeon!
(You can try this hack even if you haven't played it, it's spoiler free!)