The California-Yucatan Railroad, being built for the good of Mexico, is under siege by a gang of terrorists hoping to force its sale; no one can prove their connection to profiteer Marsden. Manuel Vega, aged co-owner, calls in the aid of his nephew James, great-grandson of the original Zorro. Alas, James seems more adept at golf than derring-do; but after he arrives, Zorro rides again! Can one black-clad man on horseback defeat a gang supplied with airplanes and machine guns?
Dr. Herbert Lee (John Paul Jones), an archaeologist seeking to decipher ancient Mara inscriptions, is aided by his son, Terry (William Tracy), and Terry's pal, Pat Ryan (Jeff York), and Normandie Drake (Joyce Bryant). Fang (Dick Curtis), a jungle pirate and warlord,plots to kill The Dragon Lady (Sheila Darcy), Queen of the Temple of Mara, and seize the treasures of her ancestors. Both Fang and The Dragon Lady have sworn death for any foreign intruders.
The period is the 1820's and the first wagon train leaves Independence heading west to Santa Fe. In order to maintain his power, the ruthless Official at Santa Fe must not let them arrive and he sends out his men to stop them. The wagon train then has to endure repeated attacks but is aided by a mysterious rider that shoots singing arrows and rides a painted stallion.
Former combat cameraman Mike Kovac is now a freelance photographer in New York City, specializing in difficult and dangerous assignments where he can get the kinds of pictures that other photographers can't, or won't take. He sometimes gets help, often reluctantly, from his contact in the police department, Lt. Donovan, and advice from his immigrant father Anton.