Donald Duck reluctantly takes his nephews Huey, Dewey and Louie to the home of their reclusive great-uncle Scrooge McDuck. Enthralled by their once legendary great-uncle and the wonder of McDuck Manor, the triplets and their newfound fierce friend Webby learn of long-kept family secrets and unleash totems from Scrooge's epic past, sending the family on an adventure of a lifetime to the Lost City of Atlantis.

Louie accidentally spends Scrooge's Number One Dime and turns to mad inventor Gyro Gearloose for help to get it back, while Dewey and Webby become entangled in a conspiracy.