In order to play this adventure, the player must complete Ep. 1 - Leaky Landing and wait 24 hours afterwards, and be at least Aunt Arctic rank 1, although it is not possible to complete the aforementioned adventure without being Aunt Arctic rank 1 or higher.
As of the 1.6.0 update, this adventure can be played without membership.
The adventure starts with the player being greeted by Rockhopper, who asks if the player will join him in searching for treasures of Penglantis, an ancient civilization. He claims these treasures were used by Penglantians to rule the seven and a half seas from Club Penguin Island. However, before the treasures can be searched for, Rockhopper wants to be sure the player is able to follow a treasure map, and tells the player to try and fish up a map in a bottle from the nearby dock. After attempting to fish one up, the player catches seaweed, and Rockhopper suggests finding something sticky to use to catch a bottle. Three crates then appear, one by the Welcome Shop at the Beacon Boardwalk, one by the band stage at the Coconut Cove, and one in the entrance of the Sea Caves. One crate contains a shipment of confetti, one contains a bunch of fish, and one contains bubble gum, which yields chewed gum. The contents of the crates are always in the aforementioned order, and which location the crate is opened at does not affect the contents.
The player is now able to successfully reel in a bottled map, which Rockhopper requests is brought to him. He takes out the map, but it is in pieces, which the player must piece together to form a map, which shows the Boardwalk, with a dotted line leading from the Migrator over to the path near the water slide. The player must follow the line which leads to a red X, which, when dug with a jackhammer, reveals a treasure chest. Rockhopper tells the player to bring it back to him. After bringing it back, the chest is opened, revealing a painting of Rockhopper, who admits he buried it himself, and that this was all a test, and the player passed. Rockhopper welcomes the player to the crew. The adventure is then complete, and the player receives blueprints for the Sea Dog's Vest and Pirate Bandana, 3 fabrics, 3 decals, 50 coins, and 60 Rockhopper XP.
Received from a crate filled with gumballs. The crate with gum is one of three crates and is either at the Beacon Boardwalk, Coconut Cove, or Sea Caves, and is whichever one of the three the player checks last. The gum is used to stick to a bottle the player is ordered by Rockhopper to fish up from the bay at the Boardwalk.
Caught in the bay by fishing with the gum. It must be brought to Rockhopper, who takes out the pieces of a map inside that must be assembled to create a map.
Assembled from the map pieces from the bottle. It displays a map of part of the Boardwalk, and has a dotted line that starts at the Migrator, goes across the Welcome Plaza, and ends at the path near the water slide.
Dug up from the red X near the water slide by digging with a jackhammer. After bringing it back to Rockhopper, it is opened, and contains a large painting of Rockhopper.