BBC America has not only released the official synopsis for the upcoming fourth season of "Orphan Black," the network's hit sci-fi series, it's also added to the acclaimed clone saga's cast.

Promising a major twist in the series' status quo, the synopsis says Sarah (Tatiana Maslany) will head off in a "horrifying new direction," ripping her and her clone-sisters apart. In the midst of all of this turmoil, Joel Thomas Hynes ("Rookie Blue") joins the cast as Dizzy, a hacker who doesn't play well within a group dynamic, according to The Hollywood Reporter.

Season 4 of the drama will see leader-of-the-pack, Sarah, reluctantly return home from her Icelandic hideout to track down an elusive and mysterious ally tied to the clone who started it all — Beth Childs. Sarah will follow Beth’s footsteps into a dangerous relationship with a potent new enemy, heading in a horrifying new direction. Under constant pressure to protect the sisterhood and keep everyone safe, Sarah’s old habits begin to resurface. As the close-knit sisters are pulled in disparate directions, Sarah finds herself estranged from the loving relationships that changed her for the better.

"Mad Men" writer Semi Chellas has also joined the series in a consultant role. The fourth season is currently shooting in Toronto, with a scheduled Spring 2016 debut.