Test of the Twins (Dragonlance Legends, Vol. 3) - Margaret Weis

Defying the fate that claimed his evil predecessor, Raistlin opens the Portal to the Abyss and passes through. With Crysania at his side, he engages the Queen of Darkness in a battle for the ultimate prize--a seat among the gods.

At the same time, Caramon and Tasslehoff are transported to the future. There they come to understand the consequences of Raistlin’s quest--and Caramon at last realizes the painful sacrifice he must make to prevent his brother’s success. Old friends and strange allies come together to aid him, but Caramon must take the last, greatest step alone.

The step into the Abyss.