"Vikings" fans are in for a treat at this year's San Diego Comic Con. The cast of the series is gracing the convention complete with clips and spoilers for season 4. Among the topics fans wish the panel will touch on is the conflict between brothers Rollo and Ragnar. 

Back in season 3, Ragnar entrusted his brother to clear the way for the Vikings as they head to Kattegat. However, it looks like the king's wish won't be fulfilled. With Emperor Charles promising Rollo land and a beautiful woman as a wife, he could easily turn against his brother next season. 

"Vikings" creator and writer Michael Hirst suggests the very possibility during an interview with Entertainment Weekly, stressing on Ragnar's battle between life and death, which Hirst said will be "very important for a while." "Vikings" season 4 will also set the stage for the brothers' fallout. 

"The other thing is that, because of what we saw happen to Rollo, I think we can surmise that one of the big events of the new season is going to be a final reckoning between the brothers, on just a much bigger scale than the first time around," Hirst revealed. 

More information about this is expected be dished on July 10 during the San Diego Comic Con, where Hirst and History EVP Dirk Hoogstra will join cast members Travis Fimmel (Ragnar Lothbrok), Katheryn Winnick (Lagertha), Clive Standen (Rollo), and Alexander Ludwig (Bjorn Ironside). 

A Vikings-themed longboat will also be recreated for the event with History promising a "sunset cruise" for attendees. While there, fans can also visit the show's Bludgeon Booth (#437) where they will be transported to Valhalla. For the ultimate experience, fans will be able to drink up in horn-shaped beer mugs in select Gaslamp districts.

"Vikings" season 4 is set to debut next year. No specific release date has been picked.