John Carter discovers that a First Born named Thurid knowns the secret of the Temple of the Sun and he and Matai Shang want to rescue the Holy Thern’s daughter Phaidor, who has been imprisoned with Dejah Thoris and another Barsoomian princess, Thuvia of Ptarth, the the Temple jail for several hundred days.

Far to the north, in the frozen wastes of polar Mars, lay the home of the Holy Therns, sacred and inviolate. Only John Carter dared to go there to find his lost Dejah Thoris. But between him and his goal lay the bones of all who had gone before.