The Silver Dwarf

To most, he's a talented apprentice and an exceptional spellshooter, but Ben is also a Guardian, responsible for uniting Elizabeth's Armour, the only artifact powerful enough to overthrow the evil dark elves. With two pieces of the armour secure, finding the third may be Ben's toughest challenge yet. His only clue is a magical key, a tenuous link to a legend called the Silver Dwarf. With the dark elves slowly conquering the Unseen Kingdoms, Ben races against time to gather the pieces of armour and unite the Guardians entrusted with them. If that wasn't hard enough, new challenges and old enemies await him at the Institute, and his friendship will be tested like never before.