In Greek mythology, Zeus, the king of the gods, fell in love with Ganymede. Zeus was so smitten that he abducted Ganymede to Olympus. Ganymede became the cup - bearer to the gods. Their relationship was one of the many complex and often otherworldly relationships in Greek mythology. Zeus's actions were characteristic of his powerful and sometimes impulsive nature.
Love and attraction are also common themes. Since it's a pairing in fanfic, there are often descriptions of how Zeus falls for Ganymede's beauty or charm. And on Ganymede's side, how he might come to love or respect Zeus despite the differences in their status. Another theme could be the journey of Ganymede. From his life before being with Zeus to his new life in Olympus, and how he adapts to this new world full of gods and goddesses.
There are various 'zeus x ganymede fanfic' out there. You could try looking on fanfic websites like Archive of Our Own. Some fanfics might focus on the power dynamics between them, like 'Power and Love: Zeus and Ganymede'. It shows how Zeus' power influences their relationship and how Ganymede copes with being in the presence of such a powerful figure.
I'm not sure which specific novel you are referring to. There could be a gay bar named Ganymede in some novels, especially those that explore diverse settings and characters in the LGBTQ+ context. But without knowing the particular novel, it's difficult to say for sure.
Ganymede in science fiction can be a key element in space exploration narratives. Some stories might feature astronauts traveling to Ganymede to study its unique geology or search for signs of past or present life. It can also be a place where there are strange phenomena, like magnetic anomalies or mysterious structures that drive the plot forward.
The name Ganymede itself has certain connotations. In mythology, Ganymede was a figure of beauty. In a novel, a Ganymede gay bar could symbolize a place of acceptance and community for gay characters. It could be a safe haven where they can be themselves, away from the judgment of the outside world.