David Innes is visiting the tribes of his empire. He is betrayed by the king of Kali and taken prisoner. As this goes on Dian his mate is testing out a hot air balloon. It breaks its moorings and carries her off to unknown lands. What follows is your basic quest of the various parties involved to find one another.
It takes them to a land across the ocean inhabited by men with bronze age technology. Along the way there are new dangers, new people and new creatures.
This is the final book in the Pellucidar series. Actually it is a collection of four stories that link together. Three of the stories were discovered after Burroughs death and published posthumously. I thought it was an exciting adventure and a good addition to the series.
My final thoughts on the Pellucidar series. I really think it was a unique idea. I am always a sucker for lost prehistoric worlds. He created a rich land full of endless possibilities.