Dragons of Summer Flame by Margaret Weis & Tracy Hickman — SPOILER WARNING

This book is the fourth book in “The Dragon Lance Chronicles” series. This book is about a mystical race called the Irda. The Irda are afraid of an invasion by the dark paladins called The Knights of Takhisis who have taken over many areas of the world they live in called Krynn. To defend themselves they find something called the Graygem to save themselves from evil. When trying to unlock the gem’s power, it releases Chaos, the Father of the Gods, out from his prison.
Chaos wants revenge on his children, and creates an army of terror. To stop Chaos, it will take everyone, good and evil, to win against Chaos. Will the people of Krynn set aside there differences, or let the world be destroyed?
Note: I would read Dragons of Autumn Twilight first, Dragons of Winter Night second, and Dragons of Spring Dawning third.