While the boys are scaring off nanny applicants, Scrooge shows the coin he got at the end of the last episode to a coin expert, who confirms it to be a coin from the Treasure of the Golden Suns, and tells Scrooge that there is another coin from this treasure over in a fortress in the Andes Mountains. Scrooge decides to go find the owner of this coin, but before he does that, he gives the job of the nephews' nanny to their most fearless applicant, Betina Beakley, who says she will work for nothing except room and board for her and her adorable and very beautiful granddaughter, Webbigail Vanderquack. After this, Scrooge meets with Gyro Gearloose, who builds a flying machine called the Golden Condor. He calls up the only pilot capable of flying it: Launchpad McQuack. Additionally, Donald's crew is in Panama, and he's been given a three-day pass, so he can temporarily join Scrooge in this expedition. Huey, Dewey and Louie are quite peeved that they cannot come along.
After picking up Donald Duck just as his break begins, the three ducks make a crash landing in the Andes. Launchpad feels proud of himself, but Scrooge orders him to climb down and find the plane. While he's doing that, Donald and Scrooge head off to meet the local antagonist - Joaquin Slowly, High Priest of the Golden Sun, who has a lot of people bowing down to him because he has a Sun Coin. The natives then start doing the same to Scrooge, since he also has a Sun Coin, much to Slowly's annoyance. Under demands by Scrooge, Slowly goes over his background, about how his ancestor, Marching Slowly, and his companion, Juan Tanamera, stole a boatload of treasure from the Valley of the Golden Suns. But the ship was then stolen by the ship's captain, who left them with one coin. The pair made a map to said valley and tore it in half. Marching happened upon these "Gold Sun!" chanters, while Juan wound up losing the other half of the map in Antarctica. As he argues with Slowly, Scrooge sends Donald to go help Launchpad fix the plane.
Launchpad, having reached the bottom of the cliff, has found the remains of the Golden Condor. He is then found by several more chanters, who want him to fly a real live condor. Donald, happening upon this ritual, helps Launchpad out by flashing his camera in the condor's eyes, allowing the pilot to take better control. Launchpad crashes the condor into the temple. Slowly resists giving Scrooge his half of the map, but reluctantly agrees to trade his half of the map for Scrooge's Sun Coin. The next afternoon, the trade occurs, but just as Scrooge expects, Slowly tells all the "Children of the Sun" that he [Slowly] is the only High Priest, and that Scrooge is an impostor. A chase ensues, with the chanters flying real condors as they chase the three ducks in their 24-karat one. Eventually, the heroes escape, and the chanters crash into Slowly. Slowly ends up dropping his coins, and they fall off the cliff. He commands his harem to go down and get them, but they refuse to obey his order now that he has lost the coins. Scrooge jettisons the plane so he can ride the currents to Antarctica, where the other half of the map is, and Launchpad drops Donald off at his crew's ship.