Orphan Black (2013)

S03E08 Ruthless in Purpose, and Insidious in Method

Rachel's vow to Sarah carries significant consequences. Meanwhile, Helena and Gracie join forces with the Hendrix family, while Donnie confronts Kellerman over his actions. At Castor, Coady and Benchman plot to locate the elusive Castor Original, and Rudy arrives at DYAD seeking a crucial asset to further their agenda.