Pellucidar
by Edgar Rice Burroughs
In this sequel, "At the Earth's Core," David Innes vows revenge and returns to Pelloucidar's Inner World to save the beautiful Diana, who has been ripped from her arms by tricks. However, her return journey takes her away from her lover's land and she is forced to make a desperate journey through thousands of miles through the violent inner world to reach her. David's epic journey takes him to the many strange lands of Pelloucidar, including the pendant bear and the Monster Shadow Country. Their intimate encounter with primitive monsters and extraordinary humans makes Pelloucidar one of the best adventure stories ever written by Edgar Rice Burroughs.