Chronicles the adventures and misadventures of Hiccup Horrendous Haddock the Third as he tries to pass the important initiation test of his Viking clan, the Tribe of the Hairy Hooligans, by catching and training a dragon.

Uhtred, a dispossessed young nobleman, born a Saxon but raised by the Vikings, forms an uneasy alliance with King Alfred the Great to fight for Wessex when the kingdom is attacked by the Danish Vikings in the ninth century.

The Danes of East Anglia and the Vikings of Northumbria are plotting the conquest of all Britain. When King Alfred's daughter pleads with Uhtred for help, he cannot refuse her request. In a desperate gamble, he takes command of a demoralized Mercian army, leading them in an unforgettable battle on a blood-soaked field beside the Thames.

It's Hiccup's birthday, but that's not going to keep him from getting into trouble. To save his dragon, Toothless, from being banished, Hiccup must sneak into the Meathead Public Library and steal the Viking's most sacred book.

"Uhtred of Bebbanburg is a man of his word. An oath bound him to King Alfred. An oath bound him to �thelflaed. And now an oath will wrench him away from the ancestral home he fought so hard to regain. For Uhtred has sworn that on King Edward's death, he will kill two men. And now Edward is dying. A violent attack drives Uhtred south with a small band of warriors, and headlong into the battle for kingship. Plunged into a world of shifting alliances...