Jake and his friends are enjoying a relaxing evening at the arcade. He and Trixie are one-on-one at air hockey, while Spud is watching them. Just as they were to the point of wrapping up the game, Brad Morton comes by and does it for them. He charges in demanding him and Trixie to leave so he and play air hockey with his hotties. Jake agrees to do so, only if he can beat him. However, when Jake goes over to get money from the cash machine, it won't accept his only dollar bill. Humiliated, Jake leaves with his lonely one-dollar bill.
Heading home, Jake is angry people like Brad get a million times his allowance, and wishes there were some way he could get cash like that. Suddenly, he crashes into a clan of Leprechauns, being chased by some Hobgoblins. Jake scares way the goblins, and the Leprechauns introduce themselves. To thank him for rescuing him, the leader of the clan Brocamas, gives Jake a golden coin, and tells him if he ever wants to see a real pot of gold, just follow the rainbow.
Later on, Jake is excited about his Leprechaun gold. But Gramps tells him that many people end up doing foolish things in the pursuit of Leprechaun gold, and advises him to give it back. But when Jake takes it to school, everyone is awed at his shiny gold coin. Jake figures with just a little more, he could rule the school. But after class, Jake notices something weird about his coin. When it shined in the light, a rainbow path was shown in the air. Jake remembered Brocamas' advice to follow the rainbow, so he dragons up, and follows it.
The rainbow takes him to Pot O' Gold, Imports and Exports. There Brocamas and his clan were running from a Giant terrorizing their shop. Jake uses his smarts to get rid of the giant. Brocamas goes up to thank him, and offers him a job for protection, and he'd be paid with lots and lots of gold to do so. Jake couldn't resist his offer. And by the next day, Jake's outfit turns into a gold track suit with gold highlights in his hair and a golden scooter.
While Fu and Gramps search through hundreds of Aztec Crystal Skull history on the internet, Jake keeps his new job from them both. During all of this, he, Trixie, and Spud celebrate to the fullest with all the gold he was getting.
After a while, Brocamas sends Jake on a secret mission down an old Hobgoblin treasure cave. A client of his is interested in a chest located deep inside the cave. Taking Trixie and Spud, the three of them pass through a ton of booby traps, and eventually find the small chest. But they are horrified to learn that the chest was for the Huntsman, and inside, what an Aztec skull!
Quickly, Jake returns to Brocamas, and confronts him about how he could do business with an evil dude like the Huntsman. He replies by saying for the gold, exactly what Jake was doing. But Brocamas quickly changes opinions when he finds out that a Aztec skull was inside. The two think up a plan to meet the Huntsman (along a squad of Huntsclan) back at the top of the cave. There, they'd have a chance to get back the skull.
Jake returns back to Gramps, where he is furious about all of this. But Jake admits his wrong, and the two begin to think up a way to defeat this whole squad of Huntsclan. Jake figures that many people would do crazy things for Leprechaun gold, and thinks up a way.
There, he and a whole gang of magical creatures meet up with the Huntsclan. With all the gold he owns, Jake persuades them to fight off the Huntsclan. He then gets a hold of the skull, just in time to escape away.
At the next day of school, the crew is bummed now that they aren't living in the riches anymore. But Jake assures it's cool, and with his new part time job, they'll probably be back in that lifestyle in no time.