Describe the pivotal role that Dian the Beautiful plays in David Innes's journey.

Dian the Beautiful plays a pivotal role in David Innes's journey, initially as a fellow captive who teaches him about Pellucidar's customs and language^[1]. David unintentionally offends her by intervening in a dispute without claiming her as his mate, which, by local custom, makes her his slave and brings her great dishonor^[1]. This realization, combined with his growing affection, becomes a primary motivation for his escape from the Mahars and his determination to find her to 'right the wrong' he committed^[1].

Upon their reunion, David explicitly realizes his love for her^[1]. Dian's enthusiasm for emancipating Pellucidar's human race further solidifies David's resolve to lead them from the Stone Age to civilization, making her an integral part of his overarching mission^[1].