The hit HBO show, "Game of Thrones," is quite known for its knack of killing off its characters. Despite this, the story has somehow still stuck to the source material and managed to not veer too far from the bestselling novels George R. R. Martin wrote.

However, Screen Rant says that this would not be the case anymore. The internationally popular author recently dropped a bombshell on "Game of Thrones" fans a couple of months ahead of the official premiere of the show's upcoming fifth season. Martin warned that they should "be on their toes" since big surprises are coming their way.

He also revealed that those who already read his "A Song of Ice and Fire" book series will be absolutely surprised by the changes in Season 5. According to Independent, not one, not two, but four characters will be meeting their demise.

Polygon says that this is actually not the first time that the show's creators opted to steer away from the source material. For instance, they changed the tone of a sexual encounter between two of the drama's characters just last season. In the book, "A Storm of Swords," the duo shared a consensual act but the TV episode showed no sign of it being consensual at all.

"People are going to die who don't die in the books," Martin told Showbiz411 at the Writers Guild West Awards last Saturday. "So, even the book readers will be unhappy. Everybody better be on their toes. David Benioff and DB Weiss are even bloodier than I am."

Season 5 will also be not the first time that the show took a bloody route. One of its most memorable episodes, entitled "Red Wedding," was also one of the bloodiest events in the kingdom.

Martin also revealed on Conan last year, as per Independent, that Season 5 will be showcasing the deaths of Walder Frey's wife, Joyeuse Erenford; Daenerys Targaryen's handmaiden, Irri; and Qarth merchant, Xaro Xhoan Daxos. Despite his mini spoiler, he still insists that anything can happen.

Sophie Turner, who plays the role of Sansa Stark, also informed the show's fans that they should expect a "traumatic" Season 5. "There're some massive moments," Turner told The Huffington Post. "Perhaps even more shocking than the 'Red Wedding' type of thing. There's a lot going on this season. There's also, you know, a lot of blood, a lot of death."

"Game of Thrones" Season 5 will be kicking off its first episode on April 12 this year.