When Scrooge and Glomgold discover a lost golf course in a mystical faerie realm, Scrooge can’t wait to share the sport with his nephews... until he realizes Dewey may be better than him at it. Scrooge’s ego puts them in danger of losing to Glomgold, and also actual danger.
Scrooge, the kids, Launchpad, and Glomgold travel to Moorshire in Scotland where Scrooge and Glomgold are competing in the annual Duckburg Billionaires Club Invitational. Webby is eager to cheer -rather over-enthusiastically for Scrooge, while Louie is entirely bored by the event. Huey is trying to earn his sports commentator Junior Woodchucks badge, reluctantly getting assistance from Launchpad, while Dewey, after learning that their ancestor Black Donald McDuck invented the sport, is eager to learn how to play. Glomgold, as usual, is bent on beating Scrooge, but fires his professional golfer caddy Tiger in favor of Louie, who is eager to make some money.
After Glomgold throws a tantrum over a coin toss, Scrooge allows him to go first, but Glomgold takes so long that Scrooge begins to instruct Dewey, who displays a natural talent. Louie's interference results in Scrooge hitting his ball off the course, where it lands in the middle of a circle of standing stones. Rather than taking a penalty, Scrooge decides to 'play it where it landed', inadvertently triggering mystical teleportation. The group then find themselves on what appears to be a mysterious golf course with no apparent means of returning home.
Two horse-like creatures then appear, introducing themselves as Briar and Bramble, the keepers of the golf course. Webby soon recognizes the pair as kelpies, mystical creatures who try to drown travelers by luring them onto their backs and into water. The two then inform the ducks that the only way to escape the course is for one of them to win the golf game. Dewey is eager to take part but a cautious Scrooge decides to take the lead.
As Glomgold and Scrooge advance, the course proves to be filled with mystical obstacles that cause them various problems. Even Scrooge's years of experience are frustrated, but Dewey is able to help when the kelpies reveal that teams are allowed in Druid golf. The group continues to move through the golf course, with Scrooge growing increasingly jealous of Dewey's natural skill and Louie continuing to provide minimal assistance to Glomgold in exchange for cash. Huey and Launchpad continue their commentary while the kelpies make every effort to try and lure the ducks into the water.
Things come to a head at the second-to-last hole, where Dewey ignores Scrooge's cautious approach and succeeds in hitting the ball into the hole anyway. Scrooge explodes at Dewey, accusing him of showboating only for Dewey to retort that Scrooge is the one who has been showing off and feeling threatened by Dewey's ability. With both Dewey and Webby disappointed in Scrooge, the group moves on to the final hole, and find an array of golfer statues.
Scrooge takes a shot only to land his ball atop a crumbling wall; Glomgold proceeds to gloat about his imminent victory, not noticing the encroaching mist. To the horror of the others, he begins to turn to stone, and they realize that the statues were once living golfers that had been turned to stone by the mist. They run to reach Scrooge's ball before they are all turned to stone forever, and climb atop each other to enable Scrooge to reach it. However, upon reaching the ball Scrooge realizes that the shot is beyond his abilities- but not beyond Dewey's.
With Scrooge's confidence in him, Dewey is able to make the shot, with the ball landing in the hole just before Dewey himself turns to stone. The ducks are all transported back to Moorshire, and the kelpies bring Dewey and Scrooge the trophy before jumping into nearby water. Glomgold too is revealed to have been saved, though his lower body is still encased in stone. Dewey declines Scrooge's invitation to play with him and Glomgold next year but expresses interest in an occasional game between Scrooge and himself.
He also references his ancestor Black Donald McDuck in the process, whose temper (similar to Donald Duck's) is the reason the sport was banned and also made him be known Black Donald.
The kelpies Briar and Bramble are obviously modeled after characters from the My Little Pony franchise: Tara Strong and Andrea Libman, both voice actors on My Little Pony: Friendship is Magic, were purposely cast as part of the joke. Lauren Faust, creator of said show, gave Francisco Angones his first job in animation on the show Wander Over Yonder.
The petrifying mist is very similar to episode 63 of the French animated TV series, Code Lyoko, where XANA attacks by conjuring up and spreading a mysterious smoke that turns everyone who comes in contact with it to stone.