The Vikings around Ragnar Lothbrok are pretty serious about their "trip to Paris," and in "Breaking Point" – set to air on Thursday – the Nordic warriors go all out for a second assault on the City of Lights, the History Channel announced.

Emperor Charles, the great-grandson of Charlemagne and last among his family to rule a united empire, meanwhile, is facing a difficult decision as he desperately tries to fend off the invasion. In Wessex, hard choices also await Judith, the daughter of King Aelle and wife of Aethelwulf, the channel added.

The Siege of Paris has already consumed three previous "Vikings" episodes, unsurprising when one recalls that historians consider the event a turning point in the fortunes of the Carolingian dynasty and in the entire history of France.

But the Viking expansion went far beyond Paris, of course, and so Michael Hirst, the creator of the History Channel hit show, should not have any trouble as he looks for stories to tell in the fourth season of the series. And the screenwriter has told Radio Times that he is, in fact, well on his way.

"So much happened in the early years of the Vikings it's incredible, which is why I wanted to start at what was essentially regarded as the beginning of the Viking age," he said.

And the English writer and producer, widely known for his movie "Elizabeth" and its sequel, is already penning episodes that probably will not air until 2016.

"I've written five episodes (of Season 4)," Hirst noted. "We're going to do more episodes this year, I think we're doing 16. I have a huge hope that we can continue (beyond that)."

The creative mind's hopes have since consolidated as the History Channel renewed "Vikings" for another season on March 26, TV.com recalled. Some 4.3 million viewers watch the series every week or record it on their DVRs, the channel's numbers reveal, which makes the show the No. 1 cable series on Thursdays in all key demographics, the website added.