After hearing about a lost Mayan treasure in class, three grad students — Nick, his girlfriend Claire, and their friend Jordy — stumble upon a clue at a local museum that connects the dots. Believing the treasure to have been hidden on Catalina, the three work out a deal with the museum's Curator to partly fund an expedition. The three want to bring the treasure to the museum, hoping to get future prospects from the publicity. They are, however, overheard by shifty Frank, whose crew of art thieves has decidedly less altruistic intentions...

The three hold a fundraiser for the rest of the money — which doesn't quite do the trick. Then a last-minute appeal to Claire's grandfather secures the funds, and they're ready. They kit up, schedule their transportation to the island, then convene at the museum on Friday, where the Curator gives them the money and his blessing.

The Boss of Frank's outfit orders Frank and associate Jimmy to shadow the group to Catalina. Once there, they realize the three intend to camp — not something these city boys were expecting. They manage to outfit themselves and erect a haphazard tent near enough to maintain surveillance. Nick and Jordy decide that their best bet are the caves along the "Silver Trail" — a trail which could easily have been named for treasure dropped along the way to a storage location.

The next day the group heads into the hills to the first cave on the Silver Trail. Frank and Jimmy follow, quickly tiring in the heat. Hiking is not their thing. The first cave produces no results, but in the second cave, the kids find marks on the walls that could be Spanish. A little digging produces... a silver piece! The group unearths a large pile of what seems to be authentic Spanish treasure. Then — Frank and Jimmy intrude, guns drawn, and take the treasure away.

Ordered to stay put for three hours, the glum trio has some time to think — and that's when Claire has an idea. Perhaps the Spanish divided up the loot, just to be on the safe side? Fired up by this possibility, the three head out to the next cave, where they find not just some gold... but a lot of gold. The main hoard perhaps! Too much to take all at once, so they load some into their packs, re- bury the rest, then head back down the hill.

With their boat having been commandeered by the bad guys, the group has to wait for the public ferry. But they return without incident, and their discovery is secured. The publicity is enormous and at the opening of the exhibit, Dr. Knight gives them a $500K finder's fee! And, he has an idea on where to find another lost hoard of gold. But... the Boss is listening, and making plans...