Proof of concept. Those three words answer one of Orphan Black’s lingering questions. Why do the clones exist? Because, of course, somebody wanted to prove that they could.

Sarah’s conversation with Ethan Duncan at the end of ‘To Hound Nature in Her Wanderings’ is a particularly revelatory one. Shot in dark and mysterious low lighting, we begin to get start to get real answers about Project Leda, and they’re not answers Rachel would be particularly happy to learn.

In that final moment, Aldous Leekie returns to his status as the show’s central villain. For a while it seemed Rachel might be the main enemy to the clones, but she’s just the result of pain inflicted upon her by Leekie, who caused the fire that killed her mother.

As Cosima says of the clones earlier in the episode, “We’re stronger together. Go figure.” It’s not like Rachel’s joining Clone Club anytime soon, but there is truth in the idea that forces mount against the clones as a collective rather than as individuals.

Rachel may think that because she’s self-aware she’s safe from this, but Leekie shows that by ignoring her orders to stop Cosima’s treatment he values the scientific research far more than her authority. The revelation that he also killed Susan speaks volumes about his goals.

It’s becoming harder to pin down exactly what drives Helena at this point though, as her deciding to ignore Sarah’s instruction to stay put doesn’t come as a surprise but her choosing to go back with the Proletheans does.

We already know that she’s scared of them and angry with them, and while she tends to be in control of situations it doesn’t seem like she knows what she’s doing in this moment. Let’s hope Sarah wasn’t faking sisterly affection last week and that she will be prepared to help Helena should she need helping.

Secrets are all over this episode, and Cosima’s beginning to feel how important they are. What’s odd is that Delphine chooses to hold back information from her too, something that feels like a reminder of how unstable the foundations of their relationship are.
We get to check back in with Alison this week too, as she’s making progress in rehab and is helped by Vic, surprisingly. Vic remains the show’s dullest character but there is something interesting about his role here as he’s being coerced by Angie, in an attempt to unravel the clone conspiracy.

All in all, this another great episode of Orphan Black.

The pace shows no signs of slowing down and there are many great scenes here, including Sarah and Helena on a road trip, Helena getting drunk and rowdy at a bar, and that tremendous final scene that suggests the potential of a clash between Rachel and Leekie, something that could have huge repercussions for the Dyad Institute.

Aired at 10pm on Wednesday 4 June 2014 on BBC Three.