The Gods of Mars

In "The Gods of Mars" (1918) by Edgar Rice Burroughs, the adventurous John Carter returns to Mars after a decade, only to find himself trapped in the perilous Valley Dor, a realm of the afterlife where escape seems impossible. As he navigates the dangers presented by the treacherous Pirates and Therns, he engages in tense battles alongside the Red Martians. Ultimately, Carter captures the malevolent Issus, but the story takes a gripping turn as he discovers that his wife, Dejah, is imprisoned in a room with an escape route that opens just once a year, setting the stage for the next installment in the Barsoom series.