The Burning Crusade

The Burning Crusade is the second book and centers around the exploits of Illidan and the Burning Legion (though there is a brief 'sub arc' around the Infinite Dragonflight). The vast majority of this book takes place in Outland. The author has stated that the story for this book will be heavily modified from its counterpart in World of WarCraft, but that the story should return to closely following the game by The Lich King.

The sidestory Tales of WarCraft: Auchindoun takes place around the same time as this story arc.

Differences Between Book and Game
In the book, Kil'jaeden allows Illidan a third and absolutely final chance to conquer Azeroth in the name of the Legion. Illidan still secretly wishes to overthrow the Legion, but he is also working for them throughout the book.

In the book, Kil'jaeden rewards Kael'thas's Dawnblade blood elves for informing him of Illidan's betrayal. In the game, Kael'thas betrays Illidan to work for Kil'jaeden, which is why he is rewarded.