Of course we must destroy this book, but not before we use it to destroy Varedis.$B$BIf we're to shut down this academy of Illidan imitators, we'll have to deal not just with Varedis but also the three night elf masters that assist him: Alandien, Theras and Netharel.$B$BGather a suitable force and return to the Ruins of Karabor.  Follow Altruis's instructions for defeating Varedis.  Hopefully his plan will work - otherwise... it'll have been a pleasure working with you.