The story starts in Barcelona where inventor Feodor together with his brother Ramon are building a flying machine in their own workshop. When Ramon is kidnapped by the inquisition, Feodor travels on his traces. He gets kidnapped by corsairs, falls in love with the daughter of a corsair captain and discovers the real reason why the Grand Inquisitor has captured Ramon. During his adventures he visits Almeria, Malta, Tripoli and finally the mysterious Zerzura.