After discovering the cause of the dragon raids in the Archipelago, Hiccup and Toothless slay the Red Death, but not before the young Haddock promises Astrid that he'll return one day stronger than ever before. It would take fifteen years for the young dragon rider to return, for he has been forged into a man, in a land called Persia, where he learns how to fight, lead armies/people, learn politics and other necessary skills. But during his time away from Berk, Hiccup makes powerful allies and enemies. An ancient evil is once again reawakened; demons called the Djinn. The Djinn have taken both man and dragons to increase their ranks to create an untouchable dark army, their leader Ghul, thirst for vengeance and darkness has consumed his reason, sense and conscience. Now Hiccup and a group of young men and women called 'The Inquisitors' are tasked to end the Djinn plague as it makes its way to the North... The Archipelago. Hiccup along with the Inquisitors and half of the imperial Persian army travel North, they must stop the Djinn in their tracks before they lay waste to humanity.

Four years after the end of the Dragon Wars, Vikings and dragons have forged an everlasting peace with each other. Greater Berk is the crown jewel of the Barbaric Archipelago, Chieftain Hiccup Horrendous Haddock III has unified every tribe in Norway, together, the Northman have made their nation more powerful then its ever been before. Unfortunately, the peace that has thrived throughout the North has drawn its dying breath. The reputation of the North and its dragons has reached far and wide, particularly to someone who despises the very idea of human and dragon coexistence. Enter, Grimmel the Grisly, he's the darkest threat that Berk and the North now face. He holds great prejudice towards dragons and is of the firm belief that they must be either imprisoned or eliminated. Any alternate ideas that involve existence are unacceptable to him. So, Grimmel brings with him an armada of elite Dragon Hunters, and with him, enemies, both old and new join Grimmel to exact revenge and destroy everything Hiccup and his people hold dear. To make matters more complicated, Toothless discovers the infamous Light Fury- a subspecies of the Night Fury, the Light Fury draws Toothless to a exotic place called the Hidden World- a secret sanctuary of underground tunnels and chambers where dragons can thrive in under Midgard. If Grimmel and the enemies of Berk and the Northman succeed in their mission, dragons will be killed and enslaved and all of Norway will be left in ashes. This war will change the world, and it will forever be immortalized in history. Witness the end of the Dragon Master's story, the end of dragons living along side humans, and witness the war that changed everything.

Five years after the defeat of the alliance between the Outcast and Berserker tribes, Hiccup and his allies discover that Cutthroat and Dagur do indeed have powerful allies. To be on guard, Hiccup and his Strike Clan establish a new fortress called Dragons Edge. A beachhead beyond Berk and the Isle of Night, where the riders can prepare for any outside threat. The mysterious figure who rescued Cutthroat and Dagur from being killed is the second in command of a man who has vowed to rise above the fear of dragons. Now, Hiccup and all his allies face Drago Bludvist and his army of both man and dragons. They will be pushed to their breaking point and for the sake of all they hold dear, they must face this enemy together; or the world will be conquered by a madman.

Hiccup is banished from Berk for befriending a dragon, a Vikings mortal enemy, rejected for the last time, Hiccup leaves Berk after the Vikings spit on his vision of peace with dragons and he is the only one who knows where the dragons nest is and the monster that sleeps within its mountains. Ten years later, the Barbaric Archipelago has heard of a new tribe called the 'Strike Clan' which is led by Hiccup and the island has become very prosperous for both man and dragons. With the dragon raids growing worse however each village pays a visit to the Strike Clan because they posses one man, that can end this madness. That man is the Dragon Master. However not all the tribes wish for the raids to end, the Outcasts and the Berserkers ally themselves and plot something that spells disaster for both man and dragons. Hiccup and his Strike Clan will protect the dragons to death if they have to, but can they stop the alliance between the two deadly tribes? Or is there something darker lurking in the shadows?

Toothless is dead. Killed by Astrid Hofferson and all of Berk praises her for slaying the infamous dragon. With the death of his best friend? Hiccup has now lost everything; first his mother, his fathers love, his peoples respect and now the only living being he truly ever cared about in Midgard is now dead. When executions are prepared for the traitorous Viking heir, Hiccup defies death and flees Berk consumed by rage, sorrow and vengeance. Believing the traitor to die at sea, Berk forgets about Hiccup entirely, but the young Viking finds a small pack of Night Furies and finds three Danish kings and queens, they unite forces and together, they will then wage a bloody and cruel war on Berk and its allies to avenge Toothless's death and to make the Hooligans of Berk every regret mistreating Hiccup Horrendous Haddock III.

Hiccup now rules Arendelle as its king, alongside his wives- Queen's Elsa and Anna, as well as their children and life couldn't be better for the royal family. Now Hiccup and his kingdom face a new challenge. During the five years of prosperity for the English trading kingdom, Danish Vikings have been swarming the English kingdoms like locusts and they are amassing another great heathen army to challenge the Saxon kingdoms of England. Not only do the English kingdoms face the army of Danes, but these Danes have in their possession something of great value towards Elsa and Anna. A long lost sister.

Snotlout Jorgenson and his lackeys do the unthinkable and assassinate Stoick the Vast and frame Hiccup for the crime, thereby banishing the heir of Berk from his home. Hiccup is sent to Outcast island and meets Alvin the Treacherous and his hordes, but the Outcasts soon learn that Hiccup has a gift. The ability to tame dragons. Hiccup tames a Night Fury with all the Outcasts watching, and with that, they all vanished without a trace. The boy finds the most ruthless and most bloodthirsty Vikings in the Archipelago for one goal. Conquest. Hiccup's army of Vikings and dragons invade Europe and their goal is to become the most infamous and legendary Vikings in history, and Hiccup himself will prove to the world he's made himself strong and becomes a conquer. Hiccup Horrendous Haddock III will become 'Hiccup the Accused.'

Hiccup never belonged amongst Vikings, so he visits Berks Seer to question the ancient one about his fate, and Hiccup learns that he is destined to thrive, yet not in Viking lands, but in the West. So, Hiccup and his Night Fury Toothless leave Berk and thrive in the English trading kingdom of Arendelle. There, Hiccup will be tested in his loyalties, faith and on the battlefield. The now ex-Viking will catch the eye of Princess Anna and soon to be Queen Elsa, both women will pour their hearts to the auburn haired boy, and he will pour his hearts to both of them. Together, the three of them will defend their home and nation from hordes of Viking and Dane invaders who wish to take and destroy everything they love. Though Hiccup and Toothless will ensure that Arendelle and England stand strong and stand firm amongst the invading Northmen. And in the act? Hiccup will receive something that his own people and his own father never gave him. Acceptance.