The story begins with Carthoris, a young man from Helium, arriving at the court of his father's friend, Thuvan Dihn, Jeddak of Ptarth. He has come to test an invention he has made, a "controlling destination compass" that allows him to travel through the air with ease and precision. The device is equipped with an "obstruction evader," which can detect and avoid obstacles in its path. As Carthoris demonstrates his invention to Thuvan Dihn and his nobles, a servant steps forward and suggests that the device might be vulnerable to tampering by an enemy. Carthoris shows him a small key that unlocks the mechanism, making it impossible for anyone to tamper with it without leaving evidence of their actions. However, the servant drops the key on the floor and then plants his sandal on top of it, crushing it. He then pretends to find it and returns it to Carthoris, who is unaware of what has happened. The servant's actions are motivated by a desire for revenge against Carthoris, who had previously foiled one of his plans. As the story progresses, Carthoris becomes aware that Thuvan Dihn's daughter, Thuvia, is promised to marry Kulan Tith, Jeddak of Kaol. He is disappointed but tries to be gracious about it, wishing her happiness with her future husband. Carthoris then departs from Ptarth, returning to Helium in his flier. As he flies through the night, he reflects on his encounter with Thuvia and the fact that she is promised to marry another man. He is still in love with her but tries to be loyal to Kulan Tith, who is a friend of his father's. The story ends with Carthoris returning to Helium, where he will continue to live as a prince and a warrior. Despite his disappointment over Thuvia, he remains optimistic about the future and looks forward to new adventures on Barsoom.
By Edgar Rice Burroughs · First published 1912 · Genre: Science Fiction, Adventure, Romance · 14 chapters