With no one else to watch them while he attends a job interview, Donald Duck begrudgingly leaves his nephews Huey, Dewey and Louie with his uncle Scrooge McDuck. With his adventurer's spirit rekindled, Scrooge decides to take them all on a mission to find the Lost Jewel of Atlantis. After this successful adventure Beakley and Donald allow the children to accompany Scrooge on further expeditions. Scrooge offers to let them all move into McDuck Manor. In the aftermath, Dewey discovers a painting of their mother adventuring alongside Scrooge and Donald.
Huey decides to throw a birthday party for Scrooge, despite everyone warning him that Scrooge hates celebrating his birthday. When Scrooge goes missing and the guests turn out to be his worst enemies, Huey decides to solve the mystery, unaware that the ghost of Scrooge's faithful butler, the long deceased Duckworth, is involved.
Scrooge and Glomgold face off in the "Duckburg Millionaires' Club Golf Invitational" in the Scottish Highlands, assisted by Huey, Dewey, Louie, Launchpad and Webby. The game is however hijacked by the spirits of ancient druids and turns lethal, with petrifying mists and a couple of kelpies attempting to have them drowned.
The kids forego their usual trick-or-treat path and instead take on the most haunted house in Duckburg, while Launchpad confronts ghosts from the past.
Scrooge and Goldie O’Gilt are turned into teenagers as they race Rockerduck to the Fountain of Youth, while the boys’ sibling rivalry uncovers danger at a spring break hotel.
Darkwing gains an unlikely sidekick as he uncovers a dark conspiracy tied to the Missing Mysteries and one of Scrooge’s employees.
With F.O.W.L. at their heels, Scrooge tests out the Money Bin’s new security system on Louie and Della, while Beakley and Webby train the others for an enemy attack.