Dragonlance Legends — Margaret Weis; Tracy Hickman

The Twins: Raistlin and Caramon, perhaps two of the most beloved characters in the annals of fantasy literature. One, an archmage who seeks to rule the gods themselves; the other, a noble warrior whose love for his brother is the reason he must stop him.
Together they travel back in time to rewrite a history the gods thought etched in stone. To ensure their own future of the world, they must travel to the Abyss and challenge the Dark Queen herself for the destiny of Krynn, and each other for peace within themselves.