Plot summary
Rachel has Paul replace Daniel as her monitor and lover, while also withholding a stem cell treatment from Cosima. Despite this, Leekie plans to treat Cosima anyway. He later confides in Cosima that the original clone genome was lost in a lab fire; the genome would have provided the cure for the illness. Meanwhile, Paul, under Rachel's orders, storms in on Felix and gets his fingerprints on Daniel's gun to frame him for the police officer's murder. He gives Sarah until morning to produce Kira. Sarah places Helena in Art's custody so she can learn more about the Proletheans.
Helena escapes, but provides Art and Sarah with clues to the location of Maggie Chen's locker. There, the two find clues relating to Ethan Duncan's location and realize that Helena intends to assassinate Rachel. Sarah finds Helena and talks her out of killing Rachel, and under Leekie's promise that he will drop the charges against Felix, the two set off to find Ethan.
Credits
Adapted from Wikipedia contributors, List of Orphan Black episodes. HTML formatting and reference markers removed.