Our tale picks up months after the cliffhanger ending of The Gods of Mars, with John Carter prowling for a way to get into the Temple of the Sun.
He backfills how he stopped anarchy by persuading the black men to accept Xodar as jeddak, and the city of Helium, Cathoris. But he's bent on the villains from last time. Indeed, finding his way into the cell leads only to his knowing that all three of the women were taken out by his enemies -- though for Phaidor he need not fear.
The tale involves getting about the Temple by shining lights, a prison known as the Pit of Plenty, two rings that react to each other once close enough, Thuvia's father coming to his aid, the fabled yellow men of Mars, his passing himself off as an aspirant to a royal guard, the faithful Woola fighting next to him, being guided by a rope, and much more.