'Outlander' season 3 spoilers: Brianna's family life to be explored?

Casting for "Outlander" season 3 has begun, and this search is vital because it will gauge the introduction of two beloved characters set to be introduced in the new season.

Executive producer Maril Davis has revealed that the show has launched its casting with showrunner Ron Moore most excited about the addition of Young Ian and Older Fergus.

Spoiler Alert! The following contains spoilers from the books by Diana Gabaldon, where "Outlander" is based, as well as "Outlander" season 3.

In the bestselling novels, Young Ian is Jamie's (Sam Heughan) nephew who escapes home to follow his uncle in Edinburgh after being threatened he will be skinned.

Young Ian also befriends Brianna, who has already been introduced in the television series. In the novels, Jamie asked him to marry Brianna, who became pregnant after being raped by a man named Roger.

On the other hand, Older Fergus is also being cast. The character, who is the adopted son of Jamie, has already been shown in "Outlander," but only as a boy. His involvement in "Outlander" season 3 connects with Ian.

Older Fergus, at least in the "Voyager" book, helped Jaime and Claire (played Catriona Balfe in the series) to look for Ian, who was taken by a ship headed to West Indies.

Fans can also expect to see Jamie's frenemy John Grey in "Outlander" season 3, but "not so much," as per Moore. Despite the popularity of the character in the reading community, he won't be a solid presence in the new season.

"John Grey is in the third book, so we're kind of taking our cues from what is actually in the third book at this point...We're not averse to it. We just aren't really bringing in the other novels at this point," Moore told TVLine.

"Outlander" season 3 is now in development and is expected to premiere early next year.