The Gods of Mars
by Edgar Rice Burroughs
At the end of Princess Mars, the first volume in Burroughs' Mars series, John Carter managed to restart a factory that produced oxygen for Barsoom and it collapsed. When he arrived, he returned to the ground and broke up with his beloved Daja Toris, Princess Helium. Ten years later, when Carter returns to Barsum and finds himself in what the locals see as "heaven" – which is not the sky at all. Carter will have to reunite with his friend, the fierce green warrior Tarcas, fight plant humans and Barsum's great white apes, break some important religious taboos, survive the evil goddess' goodness, ignite the slave rebellion, fight in the arena, and save Deju Toris in the midst of a massive aerial war between the red, green, black, and white people of Barsum. High adventures, Mars style.