Zagor and Chico meet an extraordinary individual at Fort Morgan: the French baron, Icaro La Plume, who for years has dreamed of building a vehicle capable of flying. But his attempts have always been frustrated. Even his latest flying machine, the ornitopter, crashes mysteriously to the ground. Having boarded an aerostat designed by La Plume by mistake, Chico is dragged away by the air currents until he ends up in the hands of the wicked One-Eyed Jack.
