In the first issue Frisco Bill visits a night club with his girlfriend Lupe, daughter of a local millionaire. They watch a performance by an oily dancer named Zapac and his sultry partner Amarilla. Bill is called to the telephone, where (like most heroes called to telephones) he's knocked unconscious. In his absence crooks abduct Lupe. We learn that Zapac and Amarilla are behind the kidnapping. They belong to an ancient cult called the Sect of the Serpent, a cabal of Indians led by a character named Zanco. Zanco has determined that if Lupe is married off to the Sun God, the sect will make a comeback and conquer Brazil. Zapac, Zanco, and company hustle Lupe out of town. When Bill wakes up he vows vengeance, and off we go.
The tale's structure, such as it is, resembles old Saturday morning movie serials. After the first-issue setup the story is an endless cycle of chase, capture, escape, chase, and recapture, punctuated by fist fights and gun battles. As in movie serials, nothing much changes until the final chapter. After more than 200 pages of frantic action, in issue 25 the saga is wrapped in four breathless pages. By the time the "coming next issue" blurb rolls around Frisco Bill is already deep into a new mystery.
