Hazard of Shadows — Mike Phillips

Book Two in the Chronicles of the Goblin King series. The enchanted creatures of legend still exist, taking refuge from an age of camera phones and government labs in a secret place called the World Below. After leading a revolution against Baron Finkbeiner, the despotic ruler of the World Below, Mitch Hardy has taken the throne. Unknown to him, ancient powers are at work. The Lords of Faerie seek to revenge the death of Baron Finkbeiner and recover the mysterious Blade of Caro. Soon Mitch is fighting for his life against hellish monsters, the likes of which he never imagined.