After ten years of exile on Earth, John Carter returns to Barsoom—only to materialize in the Valley Dor, the fabled Martian heaven. But this supposed paradise conceals a horrifying truth: it is a deadly trap where pilgrims seeking eternal bliss are enslaved or devoured. Facing the treacherous Therns and the piratical First Born who worship the false goddess Issus, Carter fights for survival and justice. Along the way, he discovers unexpected allies and a long-lost family member. Yet victory brings heartbreak, as Carter is trapped in darkness, seemingly separated forever from his beloved princess, Dejah Thoris.
