Scrooge McDuck is hot on the trail of the richest adventure ever. Pieces to the map of the Lost Treasure of McDuck have been scattered across the globe, and Scrooge must find them before the greedy Flintheart Glomgold grabs them. It's going to be a race to the finish as both of them try to find the treasure and become the richest duck in the world! Join Scrooge and his nephews as they explore the ancient pyramids of Egypt and do battle with swash-buckling pirates in the Bermuda Triangle. Help them search the haunted halls of an ancient Scottish castle and scale the watery heights of Niagara Falls. Aid Scrooge in his quest for the secret of the island of Mu and you'll gain the final clue to unravel the hidden location of the Lost Treasure of McDuck!

As the game opens, Huey runs to his uncle Scrooge McDuck with a torn piece of paper, which is a piece of a treasure map drawn by Fergus McDuck. Inspired to discover the hidden treasure left by Fergus, Scrooge starts an expedition to find the missing pieces, unaware that his archenemy Flintheart Glomgold is also after the lost treasure of McDuck.

Scrooge travels to Niagara Falls, a pirate ship in the Bermuda Triangle, Mu, Egypt and Scotland. Each area has its own unique treasure that is guarded by a boss. After all five main stages are cleared, Webby is kidnapped by Glomgold and held for ransom on the pirate ship in the Bermuda Triangle. Scrooge arrives and gives Glomgold the treasures, only to discover that this "Glomgold" is actually a shapeshifting robot called the D-1000 programmed to destroy him. After the D-1000 is defeated, Glomgold sinks the ship and tries to take Scrooge and the treasures with it.