Back in the mid-2000s, few television shows had as rabid fanbase or as rich a mythology as Lost. That ABC mystery series masterfully handled an ensemble cast, and while many fans and critics lost faith in the storytelling in later seasons, the cast - which included Emmy winners Terry O'Quinn and Michael Emerson - remained one of the show's highlights throughout its six-season run.

More recently, HBO has inherited that same sense of fan loyalty, critical praise and gifted cast of memorable characters with Game of Thrones. In fact, the show is more than one of the network's biggest hits ever, but it has proven to be one of the most-talked-about series on the air in general. Now, as the show ramps up for season 5 in spring of next year, a Lost alum is poised to join its cast.

According to THR, Adewale Akinnuoye-Agbaje - who played fan-favorite Mr. Eko during the second and third seasons of Lost - will join Game of Thrones as a character named Malko. However, fans of George R.R. Martin's novels shouldn't bother searching their bookshelf to refresh their memory of what role he plays in the ongoing saga. Akinnuoye-Agbaje's character is an original creation for the show.

Game of Thrones Lady Stoneheart

The news that Game of Thrones is bringing on the actor to play someone not featured in the source material may upset purists, but the show has already proven it's not afraid to differ from the books. Add to that news that the upcoming season will feature flashbacks for the first time, and the possibilities of how Akinnuoye-Agbaje's character will figure into the story are essentially endless.

It's no surprise that the actor - who has also starred in films like Thor: The Dark World and G.I. Joe: The Rise of Cobra - would jump at the chance to be a part of Game of Thrones, given the show's monstrous worldwide success and status as an award-winning critical favorite. With a handful of films in development, Akinnuoye-Agbaje has certainly stayed busy. Still, fans will have to wait until the season debuts to get a better idea exactly how integral his part will be in George R.R. Martin's world.

In the meantime, let the speculation begin. How do you think Akinnuoye-Agbaje's role fits into the larger story of Game of Thrones, Screen Ranters? Sound off in the comments section below with your thoughts.

Game of Thrones returns with season 5 on HBO in spring 2015.

Source: THR