The Mad Mage's Academy

From publisher blurb: Welcome to the Forgotten Realms Endless Quest books, where you don’t just read a fantastic tale. You become the hero — and choose your own fate. You have been tasked with stealing the spell book of Halaster Blackcloak, the mad mage who controls the halls of Undermountain. The book is secreted away inside the halls of a magic academy, so you must navigate your way in by posing as a new student. But you need to move quickly in order to locate the spell book, steal it, and get away without being caught by the mad mage himself. Be on your guard, rogue.