The kids must stop Scrooge's unhealthy obsession with a few missing coins to keep him from becoming the next Glomgold.
At the Money Bin, Huey was attempting to convince Scrooge to stay resting for the day after he had developed a small fever. Nevertheless, Scrooge detested by believing that a stuffy nose and clogged ears wouldn't kill him if he continued his daily work routine for the day. Soon after, Manny was exiting the elevator with a set of tools and asking Scrooge using a supposed sign of morse code about where to place them, but Scrooge believed Manny was telling him about how sick he was and shooed him off. Later, Scrooge entered his vault and decided to go for a little swim in his money before his morning meetings started. But as he was doing so, he realized some of his coins had been taken from his bin.
Meanwhile, in Glomgold's quarters, Owlson is reminding Glomgold of the wager competition so they would need to look respectable. Glomgold who is sleeping on the job has just thought of the perfect scheme to become richer than Scrooge and usurp his company. Then Owlson reminds her superior of N.E.S.T., which is "No Elaborate Schemes Today". Because Glomgold and Owlson run a multi-million dollar business, the latter hopes the company can do some good for once instead of evil plans. To get even with Scrooge, Owlson suggests Glomgold be more cautious as Scrooge is.
The stressed Scrooge then bursts in and accuses Glomgold of thievery from the Money Bin. Scrooge then orders Manny to see Glomgold and Owlson to the door outside. He then orders that only authorized personnel to be allowed in the Bin.
Huey, Dewey, and Webby are then given a demonstration of Scrooge and Gyro's anti-intruder methods for the Bin said to wreak maximum havoc on thieves purloining from the Bin, such as Donald getting zapped by an electric fence and hit by a pad, surrounded by fire and nearly run over by spiked balls. If the intruder is captured, they would be placed in storage to await experimentation for Operation Gyrubutapocalypse. After refusing another meal, Scrooge calls up Gizmoduck.
Outside, Gizmoduck shows potential suspects; Glomgold is currently with Owlson, Mark Beaks is live posting at Crowchella and the Beagle gang are at ConCon (convicts convention), but no word on Magica de Spell as of late. Huey suspects Scrooge's nasal passages are clogged. Louie then rushes in worried about his own business profits; Scrooge points that eighty-seven cents were stolen. With the Bin compromised, Scrooge remembers his "smarter than the smarties" speech but his coins are not in his pockets.
As the kids count the coins in the bin, Huey suggests that Scrooge get some rest and worries his personality may seem off for some reason. According to the Junior Woodchuck Guidebook, Scrooge has the symptoms for Gold Fever, which is caused by an extended exposure to gold. These symptoms would be confusion, itchiness, paranoia and outlandish extremes which could result in a fatality. Webby assures that Scrooge bought out a country to save up postage, then Scrooge on the speakers puts the Money Bin on lockdown. The entire bin is sealed off and surrounded by steel plating and security lasers.
Scrooge, about to go over the edge, broadcasts that his "wee ones" were kidnapped from the Bin: Two quarters, two dimes, some nickels, and some pennies. The elder duck then issues a bounty of two million on whoever stole the eighty-seven cents. Louie also suspects the gold fever will overtake the triplets' great-uncle. Scrooge then says he has the Bin surrounded by a full arsenal, and challenges someone named Chester to try and a break-in. With his spats pilfered, Scrooge has to wear makeshift tissue boxes. Huey tries to suggest rest, but is on deaf ears as Scrooge shows an axe in his cane. Webby is confused as to who Chester is, to Scrooge he's the unknown and question.
Scrooge, his points out "Chester" is a distance away, and Dewey gives chase just as Scrooge orders Gizmoduck to fire on the thief. From Gizmoduck's view, the thief is nowhere to be seen however, but activates his missile launchers. Huey tries to warn his friend that Scrooge is not of sound mind, but the great-uncle orders firing anyway. Unfortunately, Scrooge's banging causes Gizmoduck's missiles to discharge and hit the Sunchaser. Gizmoduck tries to save Launchpad but the Helmetcopter does not activate. With Dewey in the way of the falling plane, Gizmoduck races to rescue the blue-shirted duck and does so in the nick of time, while the Sunchaser has crashed as usual.
Roxanne then reports "Bridgemageddon" pointing Scrooge to be the cause of the disaster. As a result of McDuck's eratic behavior, investors plan to give his money to the more stable Glomgold Industries. Glomgold seems to delighted by the news and proclaims himself "more stable" than his arch-nemesis. Scrooge continues his hunt for "Chester" when Gizmoduck reports a break in; It turns out to be his family and friends trying to again warn him about his condition. While Webby hopes the thief will be caught, Huey fears that his great-uncle is diagnosed with Gold Fever which would be lethal if he were to be exposed to more gold.
Dewey accuses Scrooge of the former nearly getting killed during the bridge incident. Manny takes Huey's side hoping to find a cure. Branding his great-nephews traitors, Scrooge further explains about Chester the inter-dimensional imp, attacking him from out of nowhere and accuses the "imp" of everything that's happened to him thus far. With Scrooge losing body weight his clothes hardly fit him. Webby seems to accept Scrooge's stories about "Chester" and insists he sleep away from gold for a while. But Scrooge refuses and wants to count his money.
Huey reasons that if Scrooge jumps into his money in his state, the fever would kill him. All attempts to keep Scrooge off his gold end in failure, as the elder duck forces the group off and prepares to dive in.
On another news report, Roxanne reports Glomgold's stock is skyrocketing thus crowning Glomgold himself the "Richest Duck in the World". Glomgold is informed of the good news by Owlson and laughs maniacally, while it is then reported that Scrooge has succumbed to Gold Fever.
A funeral is held at McDuck Manor, with Donald crying at his fallen uncle's casket before storming out. Gizmoduck solemnly plays bagpipes. Glomgold then makes his entrance dancing triumphantly in a new head-to-feet white suit before announcing his victory to the lifeless Scrooge. The funeral gathering gives Glomgold scornful glares while Owlson is shocked. She drags her boss to a seat to inform him that Gold Fever killed him. She then gives Glomgold a lollipop to distract him from saying anything further.
Huey then gives a speech over all the things Scrooge has taught throughout his years, the most important is to listen to family. Now that Scrooge is dead, the red-shirted duck decides to accept the hypothesis; If Chester is indeed real, he would have plotted a scheme so elaborate as the perfect scheme. In the end, a villain could never have pulled off a scheme as the one the heroes were facing. Glomgold then admits he was the perpetrator behind everything and used the Time Teaser device.
Earlier when Manny was dumping out waste, the Time Teaser rolled unexpectedly to Glomgold when Scrooge hit the garbage cart. He then accidentally froze time and explored the world of frozen time not getting as much as one reaction from anyone, including having a starring contest with a baby for a year. When he returned to his quarters, Glomgold restarted time and supposedly became master of time itself. He then froze time and snuck to the Bin, attempting to heist with comical failures, but he came to realize that even swiping a small amount would drive Scrooge insane, so he managed to snag the eighty-seven cents, thus driving Scrooge off the deep end. Glomgold next took the opportunity to snatch the elder duck's spats and wrote the document about Gold Fever planting it on Huey's guidebook. Next, Glomgold toyed with the family by giving Scrooge itches, sabotaging the Helmetcopter, gluing it shut, defacing Scrooge's office with his saliva and tearing McDuck's coat to almost unwearable length.
Suddenly, "Scrooge" rises out of his coffin and slaps Glomgold with a hoof. It is actually Manny in disguise. A stork wearing brown sheds his disguise and Scrooge is indeed still alive. Just when Scrooge was about to dive into the gold, he sneezed and realized he was sick after all, and they found the forged document of Gold Fever leaving the book. Having rested for a whole day, Scrooge and his family learned that Glomgold was posing as "Chester" as part of his scheme to cheat the wager. Huey also recorded Glomgold's fraud plan, thus re-crowning Scrooge as "Richest Duck in the World". Donald walks back in and is elated to find Scrooge alive before fainting due to not having been informed of the scheme on the McDuck's part.
Scrooge reminds Glomgold that the latter's victory was impossible, as the former has his family to rely on. This results in a brawl breaking out for the Time Teaser watch. As Scrooge and Glomgold fall out, they reverse the Time Teaser, being frozen in midair. Night falls, then Beakley intervenes and Louie advises faking Scrooge's death again should Scrooge go insane again. Beakley loosens Scrooge and the Time Teaser, then restarts time for them, but with Glomgold landing hard on the ladder with injury. Scrooge thanks his housekeeper, then takes back his eighty-seven cents before licking his own saliva onto Glomgold's glasses to humiliate him before bidding him good night taunts.
The title refers to The Seven-Per-Cent Solution, a Sherlock Holmes novel written in 1974 by Nicholas Meyer. It became a film in 1976.
The episode borrows elements from The Twilight Zone episode, A Kind of a Stopwatch.
Gold fever is a nod to the 1987 series episode "Too Much of a Gold Thing", where it is a real disease, albeit not (inherently) fatal.
This episode reveals that Magica's location is unknown after the event The Shadow War!.
The scene where Donald and Gyro test out the security system appears to be a reference from a clip from the 1987 theme.
Scrooge contracts gold fever in the Carl Barks written comic story The Fabulous Philosopher's Stone. The Philosopher's Stone grants Scrooge the power to turn everything to gold. Scrooge has to stop using the stone because it slowly begins to turn him into gold.