Adventure is afoot in the small coastal town of Emerald Cove. Dave Shipper (John Weisbarth) is all set to enjoy a quiet summer, but the arrival of his cousin Jon (Frank Jimison) throws a wrench in his plans. Rather by chance, they happen upon an old map that sets them on a quest, along with Dave's friend Freddy (Freddy Rible), to seek out a legendary treasure said to be buried deep inside the ocean cliffs. With the help of an old local fisherman ("Smokey" Tom Hodgins), the boys compile clues that unravel a 30-year-old murder mystery and lead them closer to their prize. They quickly draw the attention of a bumbling crew of malicious treasure-hunters and a mysterious pickaxe-wielding "digger", all intent on capturing the gold for themselves.
Toby appears to be an ordinary dog living the simple put life, but unbeknownst to his family, he moonlights as secret government operative, Agent Toby Barks.
After being shanghaied in a plot to have him declared dead and take over his ranchero and other properties, Don Ricardo, disguised as a peon, returns to Old California, and begins the fight to reclaim what is his.