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.
Check out the promo in the video below.
Returning this season is Jordan Gavaris as Sarah's battle-worn foster brother Felix; Maria Doyle Kennedy as Sarah and Felix's foster mother Mrs. S; Kristian Bruun as Donnie, Alison's partner-in-crime and husband; Kevin Hanchard as Art, Beth's detective partner who's torn between his job and his loyalty to the clones; Skyler Wexler as Sarah's long-suffering daughter Kira; Ari Millen as a mysterious new Castor clone, the likes of which we've never seen before; and Josh Vokey as Scott, Cosima's lab partner. Also returning this season is James Frain as Ferdinand, an intimidating "cleaner" for shadowy organization, Topside; Allison Steadman as Kendall Malone, "the original"; and Rosemary Dunsmore as Susan Duncan, Rachel's adoptive mother and one of the leading scientists of Project Leda. Joining the Orphan Black cast this season is Joel Thomas Hynes as Dizzy, an edgy, self-reliant hacker who doesn't conform to group mentality.
Orphan Black season 4 will premiere on BBC America in April 2016.