This is the 20th episode of Pac-Man and the Ghostly Adventures. It aired on September 28, 2013.
After Dr. Buttocks get a map to a underwater city called Paclantis, Pac-Man, Spiral, and Cylindria are sent to Paclantis to find a youth berry tree before Betrayus finds it. The Ghost Gang are also trying to find it so they can restore their bodies. It's a big underwater race to get the youth berry tree.
This episode is based on the underwater legend, Atlantis.