Vikings season 3 premiere spoilers: King Ragnar and Lagertha to attack the impenetrable city of Paris?

Viking season 3, History Channels' magnum opus, will return in a month and fans are excited to learn more about the fate of their favourite King Ragnar and his possible reunion with former wife Lagertha.

As of now, the legendary Norse ruler killed Horik and much of his family to become the King of Denmark. He and his son Bjorn obtained Horik's sword in season 2.

But in an unexpected move, Ragnar spares Erlendur, Horik's son and let him go, which fans suspect might be a fatal decision by the new King of Denmark.

Show creator Michael Hirst has revealed that Ragnar and his group of Norsemen will not stay still when the season 3 returns in February. Rather, they will endeavour to what the show creator describes as their biggest adventure ever in the historical drama with the raid on Paris.

The official synopsis for season 3 reads: (via The Mary Sue)

"With the promise of new land from the English, Ragnar leads his people to an uncertain fate on the shores of Wessex. King Ecbert (Linus Roache) has made many promises and it remains to be seen if he will keep them. But ever the restless wanderer, Ragnar is searching for something more ... and he finds it in the mythical city of Paris. Rumored to be impenetrable to outside forces, Ragnar and his band of Norsemen must come together to break down its walls and cement the Vikings legend in history."

However, apart from the attack Paris plans, Ragnar Lothbrok may face serious family issues as his teen son Bjorn is slowly withdrawing himself from his father and is getting close to uncle Rollo.

Aslaug, who gave birth to a crippled son in the last season, might stand as more trouble for the king who is already attracted to his former wife and saviour Lagertha.

"Our leads start in a bad place. They're in dysfunctional relationships of one kind or another and there's a lot of resolving to do," Hirst told Yahoo News about the problems Ragnar may face when the show returns.

"We keep increasing the scale as they did historically. We started with one long boat and 30 warriors attacking an isolated monastery and Paris involves 100 boats and 3,000 warriors. All are in serious jeopardy. Killing people off is inevitable," Hirst added.

The battle for the Mythical city of Paris will also include new characters including Kalf (Ben Robson), Harbard (Kevin Durand), Emperor Charles of France (Lothaire Bluteau) and Princess Gisla (Morgane Polanski).

Vikings premiers on 19 February on the History channel.