chunk: Subsequently Carter becomes embroiled in the political affairs of both the red and green Martians in his efforts to safeguard Dejah Thoris, eventually leading a horde of Tharks against the city-state of Zodanga, the historic enemy of Helium. Winning Dejah Thoris' heart, he becomes Prince of Helium, and the two live happily together for nine years. However, the sudden breakdown of the Atmosphere Plant that sustains the planet's waning air supply endangers all life on Barsoom. In a desperate attempt to save the planet's inhabitants, Carter uses a secret telepathic code to enter the factory, bringing an engineer along who can restore its functionality. Carter then succumbs to asphyxiation, only to awaken back on Earth, left to wonder what has become of Barsoom and his beloved.