Huckerby M., Ostler N.: Defender of the Realm. Dark Age

The action-packed second book in the Defender of the Realm trilogy! After the great battle at King Alfie's coronation, the nation thinks it's seen the last of the Black Dragon, and Alfie gets busy learning what it means to fill his father's shoes. But when a band of undead Vikings appears, Alfie, Hayley and the rest of the Yeoman Warders fear that Professor Lock is back to finish what he's started. For the epic battle that's brewing, Alfie will need to enlist help from abroad, as well as from a mysterious new friend who seems to be watching over him... .