Orphan Black reveals the greatest secret of Sarah's past

We're in the penultimate episode of the season, and Orphan Black just keeps throwing revelations at us. Sarah learns about her past—and gains some unexpected family members. Alison has an intervention, and Dr. Leekie tries to convince us he's one of the good guys. Spoilers ahead.

Last week ended with the most shocking, heartbreaking moment in the entire season when Kira was struck by a car. This may be the first time that Sarah has encountered a problem she couldn't talk her way out of, and it involves the one person she's truly cared about from the start. It's a true moment of panic.

In an earlier episode, Cosima told Sarah that the clones were her biological imperative, but it increasingly seems like all the clones view Kira as theirs. Alison has children of her own, but can't help but feel something for her genetic flesh and blood. For Helena, meeting Kira was a turning point, giving her what she didn't have before: a family.

Orphan Black reveals the greatest secret of Sarah's past

The tension of whether Kira lives is broken early. In fact, she's made a miraculous recovery. But that adds another question: how is Kira alive? She bounced off of a fender last week, and this week opened with a lot of blood. Cosima wonders if Kira might have some sort of lizard healing factor. Hmm, who else do we know who has shown a superhuman ability to sustain physical damage?

Cosima's little lab buddy has discovered that the clones aren't quite identical after all. There's what appears to be a genetic barcode in each clone's DNA, which explains how Leekie is able to tell the clones apart. It only makes sense, although the barcode will probably be doubly interesting given this episode's biggest revelation.

Helena has returned to Tomas (whose name I've been erroneously spelling Thomas) empty handed. Tomas is stunned to discover that Kira is really Sarah's child (he didn't believe it was possible) and he tries to convince Helena to lure Sarah into a trap. But that encounter with Kira has left Helena changed, and she lashes out at Tomas, prompting him to lock her up.

Orphan Black reveals the greatest secret of Sarah's past

Meanwhile, Paul gets some bad news. Leekie knows all about Sarah, and he wants to meet her. Paul thinks it's not a terrible idea; he figures most of the cards are on the table, and meeting with Leekie can only mean more information. Cosima advises her to give Leekie a chance, insisting that they must care about the clones.

Leekie doesn't go full info-dump on us, but he does reveal a few things. He claims he's not the big cheese of the experiment, just the rat in charge of data collection. He also says that Tomas is a member of a religious extremist group called the Prelethians (or Prolethians; if someone with access to captions can help on that one, I'd be grateful). I do love that the show again makes fun of itself and its own conventions, with Sarah deadpanning that "Neolutionist is much better." Maggie Chen was a member of the group, but infiltrated the Neolutionist organization.

Orphan Black reveals the greatest secret of Sarah's past

What does Leekie want? At the moment, Helena, his "white whale." He promises that he doesn't want to harm her, just deprogram her, but Sarah doesn't seem convinced.

While Sarah considers allying herself with Leekie, Cosima and Alison are having more domestic disputes. Cosima finally confronts Delphine about her association with Leekie, and even fessed up that she knew Delphine was a spy from the start. Last episode, Delphine seemed to be feeling a little ambivalence about spying on Cosima, and now that everything's in the open, she still insists that she's on Cosima's side. I'm interested to see how this plays out. How will their relationship move forward from here? Will Delphine's loyalties ultimately fall on Leekie's side or Cosima's? It would be a horrible cliché to kill off the lesbian lover, but I'm suddenly very nervous for Delphine.

Alison and Felix run by Alison's house to grab a few things, and find Donnie, along with Alison's pastor and all their friends and neighbors, waiting for her. They're staging an intervention, and Aynesley is her perfectly awful self, telling Alison that she's hurt less by Alison sleeping with her husband and more by Alison's rejection of her friendship. Yeah, the sugar-coated guilt trip isn't making you look any less suspicious, lady. Felix advises that she play nice and "live to fight another day," but instead Alison goes on the offensive. She sends Aynesley a clear, coded message, one that sounds to everyone else like she's accusing Aynesley of being a run-of-the-mill gossip, but when Alison refers to herself as a "laboratory subject," Aynesely's eyes go momentarily wide. By the time Alison reaches a boil, even Donnie realizes the intervention was a terrible idea, laying a hand on her should as he ushers everyone out.

Orphan Black reveals the greatest secret of Sarah's past

Sarah does end up fetching Helena. After momentarily contemplating shooting her, she decides to release her from the cage instead. Helena surprises her with a hug, and Sarah seems to actually feel for her clone. And then comes the showdown that Helena has been building up to all season, the one where she has to decide between Tomas and Sarah. But Tomas only offers violence and ridicule, while Sarah suggests a possibility more terrifying than Tomas' abuse of Helena: that he would visit the same violence upon Helena Kira. Sarah just barely stops Helena from stabbing Tomas' eyes out and locks him up in his own cage.

Art and Angie haven't been slacking off this episode, either. After failing to squeeze more info out of Sarah (whom he still believes is Beth), Art reviews the footage of the death of "Sarah Manning." He realizes that it's Beth who jumped in front of the train, and that the woman he's been dealing with must be Sarah.

Orphan Black reveals the greatest secret of Sarah's past

Sarah planned to deliver Helena to Leekie, but Mrs. S calls her home with Helena in tow. Mrs. S' contacts found Amelia, a South African woman who gave birth to Sarah. Years earlier, Amelia had agreed to be the surrogate to a wealthy couple in London, ones who spoke of their Neolutionist philosophy. But when she realized that the couple were scientists, not prospective parents, she decided to hide the babies she was carrying.

Babies? Amelia gave birth to twins, and gave one up to the church and one up to the state. Helena isn't Sarah's clone; she's her twin sister. Assuming they split from the same embryo, does this mean that Helena and Sarah share the same barcode DNA sequence?

Orphan Black reveals the greatest secret of Sarah's past

That's not the only big revelation from the end of this episode. After Sarah fails to make the rendezvous, Leekie takes a call from a mysterious woman. We don't see her face, but could this woman be the original? Or is she another clone involved in the Neolution organization? It looks like we'll be meeting her again next week in the season finale.