John Carter flees across space under a borrowed alias after a treacherous commanding officer frames him for treason, waking up stranded upon the barren red plains of Mars. Captured by towering four-armed Thark gladiators, he earns respect through lethal arena duels and forms an alliance with Dejah Thoris, an abducted Helium princess escaping an unwanted political union.
When hostile warlords lay siege to Dejah's desert citadel, Carter unites warring tribes to mount a fierce planetary counteroffensive. To preserve the atmosphere before rival saboteurs choke out all life, he must brave crushing heights and hostile legions to secure the dying realm's survival.
