The Lucky Mermaid is a floating gambling hall on the Mississippi River a paradise for gamblers. Here Zagor and Chico meet the hopelessly unlucky card player Three-Sevens, the enigmatic Colonel (a man with a mysterious past) accompanied by the native Raphael, the cheerful Black guitarist Fats, and an old acquaintance: the charming Gambit.
But aboard the Lucky Mermaid, a ruthless killer is at work he beheads his victims and shrinks their heads, turning them into tsantsas, in the tradition of the Jivaro people.
What are Amazonian natives doing in North America? And what is the Colonel’s dark secret? In truth, he was once an evangelical priest and missionary in the Amazon. He returned to the United States with Raphael to avenge the massacre of an entire Jivaro village, an atrocity committed by the man now living under a false identity as Andros, owner of the Lucky Mermaid.
Zagor manages to capture Raphael, the headhunter, and in the final shootout with the ship’s crew, the Colonel, Raphael, and Andros are all killed. After spending a passionate night with Gambit, Zagor resumes his journey alongside Chico.
