Robert Raids Harold's Castle

This is the second book of a series. Robert has to return to the Land of Lost Children to do battle with another evil sorcerer. The sorcerer probably has a trap set for Robert in the castle, so Robert needs to lure the sorcerer out into the forest to do battle.
Buy this book and join Robert as he battles castle guards and apprentices, which leads to a final duel of magic with the evil sorcerer.