When a depressed Bobby Duval abandons his beloved horse, Maize, outside his friend Hardy's veterinary clinic, Sheriff Mitch Downey realizes something is very wrong. Fearing that Bobby is suicidal, Sheriff Downey places him in temporary custody. After first refusing to speak, Bobby begins ranting incoherently about a map and treasure. Suddenly, he turns ashen, crumples to a heap on the floor of the jail cell, and dies, leaving his land and its alleged treasure to an unprepared Hardy. Before he dies, he offers a final, ominous warning: they will kill for it. Soon, the town is flooded by an unknown water source, and Hardy suspects Bobby's defunct mining operations are responsible-but when he explores his newly acquired land, he discovers more than water in the dangerous and enchanting caves and tunnels. Unfortunately, Hardy is not the only one who knows of the secrets hidden in the caves. Bobby has told the wrong people about his discoveries-evil people-and Hardy and his team must beat them to the riches or face indescribable horrors.