* Hades's Role: Hades is often misunderstood as a villain. In Rick Riordan's world, he is a powerful god who is rightfully in charge of the Underworld. However, he's depicted as a stern, even grumpy figure. This contributes to the overall sense of darkness and discomfort in the Underworld.
* Symbolic Representation: The Underworld serves as a symbolic representation of death and the unknown. This creates a sense of danger and fear for Percy, who is facing the ultimate challenge of retrieving Zeus's lightning bolt.
* Character Development: The journey to the Underworld forces Percy to confront his own fears and limitations. He learns to rely on his friends and his own strength to overcome obstacles.
* Theme of Justice: The Underworld plays a crucial role in the overall theme of justice within the book. Percy must navigate the Underworld to prove his innocence and restore balance to the world.
* Mythological Connection: Riordan's use of the Underworld is rooted in Greek mythology, where it is a place of shadows and death. By incorporating this aspect, he adds depth and historical relevance to the story.
While not specifically called "hell," the Underworld in *The Lightning Thief* serves a similar purpose. It's a place of darkness, danger, and judgment, making it a compelling setting for Percy's adventure and a vital element in the overall story.