Long ago, there was a mystical kingdom called Atlantis located to the west of the beautiful city of Eden. Generations of Angels lived and worked there in peace. However, this peace was soon overwhelmed by the ferocity of war. After the war, Atlantis was torn from the land and sunk beneath the waves. Even after this tragedy the people of Eden sought peace. Recently, scientists from the Iron Castle Exploration Association have found the exact location of Atlantis. The first cooperation among four factions in history was created. They have created a great exploration ship, Habosen, and planned to go to Atlantis. While Angels all over Eden cheered their bravery and hoped for the best, evil shadows gathered under the water.
Several days ago, Habosen was suddenly attacked and sunk beneath the waves after it finished the quest on its way back to Puqi Island. Mamen, the leader of the Evil Lyceum, stood on board the Habosen and gazed at treasures obtained from the cabin. He murmured, "All from Atlantis belong to me. Why did you ask someone to take them back from me after you destroyed them? I swear I will take every last item back.".
Because of the incident, people on Puqi Island became anxious. They are unable to even leave Palm Base. Evil shadows under the water have become broader and broader. Are there any survivors of the Habosen disaster? What's the secret in the ship? What's the relationship between Mamen and the lost kingdom of Atlantis? A series of riddles await Angels. Are you ready to face the new challenge now?