Plot summary
Kira is taken to the hospital, where it appears that she has accelerated healing. Alison returns home to find that Aynsley is holding an intervention regarding her past behavior and addictions. Under Felix's encouragement, Alison turns the tables by scrutinizing Aynsley. Art finds CCTV footage of the train station where Beth committed suicide, and discovers that Sarah has been impersonating her. Cosima learns that Delphine leaked the names of the clones to Leekie and confronts her. Delphine reveals that she knows about Kira's existence but decided not to tell Leekie, knowing her life could come into danger should he know (Kira is the only known biological child of a clone).
Sarah meets with Leekie, who wants her to save Helena from the Proletheans, the extremists who indoctrinated her. Tomas punished Helena for defying orders, but she is later rescued by Sarah and turns against Tomas. Sarah returns to Mrs. S, who has reached her contacts in England, and meets Amelia, Sarah's birth mother. Amelia reveals that she gave her away and fled after realizing she was a surrogate mother to Dyad scientists. Furthermore, Amelia gave birth to twins; Helena is Sarah's twin sister.
Credits
Adapted from Wikipedia contributors, List of Orphan Black episodes. HTML formatting and reference markers removed.