After foiling the Beagle Boys, Scrooge and his nephews decipher the strange marking on the map, which leads to a sunken treasure ship in Ronguay. However, Flintheart Glomgold and El Capitán are out to stop them at every turn.

The nephews, Webby, and Mrs. Beakley find themselves joining Scrooge in his adventure as he looks for the second half of the treasure map in Antarctica.