Well that was kind of predictable, right? This week, Orphan Black made a connection between the Leda and Castor clones that you could sort of see coming, but that didn’t make “Formalized, Complex, and Costly” any less riveting — the real twist, though, came at the end of the hour. That death wasn’t one I saw coming.

This week’s big reveal, of course, is that the Leda and Castor clones come from the same donor, effectively making them brothers and sisters. But the Castors aren’t ready to start singing campfire songs with their new sisters just yet. Imagine if and when they do combine forces, though! Sarah’s familial revelation to Mark is a bit more than he can handle. We know the Castors have a tendency to be temperamental and aggressive. Rather than deal with problems and stressful information by taking their time to reflect and reason (like the Ledas, save for Helena, maybe), every emotion is processed with aggression.

While Helena is still being kept locked up on the military base, Sarah, Felix and Cosima (and Scott!) have to deal with the little problem of Seth’s corpse, resulting in the most grisly and gory scene in Orphan Black history. Scott is not handling it well:

And elsewhere, Alison and Donny are doing quite well with their new enterprise. I enjoy these little detours into the suburban life of Alison and Donny, although they do feel a bit segregated from the main plot, since Alison pretty much refuses to get involved with the serious stuff these days. Alison and Donny have their very own sitcom within the Orphan Black universe, but I do hope they rejoin the rest of the girls soon.

As for Rachel, she’s got a long road to recovery ahead of her, since her brain was a bit scrambled by that pencil in her eye. She has trouble forming words, and Dr. Nealon’s flashcard exercises appear to have an ulterior motive. Delphine remains in charge of Dyad, a bit different from the sweet Delphine we once knew. Although she’s still helping the Leda women, she’s taking a cold approach to it.

But the real story this week is with Mark and Gracie. He admits that he was sent to the farm by the military to retrieve tissue samples, and even though Sarah tells Gracie that Mark is a clone, she accepts him anyway. The Proletheans may be down, but they’re not out. Sarah and Art approach the midwife, who still holds firm to their cuckoo ideals. Gracie retrieves the box Willard Finch was holding for her father, assuming it contains what Mark is looking for, but it’s a bunch of useless junk. Mark arrives at Willard’s to discover Sarah, who delivers this hilarious line with a straight face when she tells him they’re family:

WE DID THE SCIENCE REAL GOOD-LIKE, MARK. I imagine Cosima would have made that reveal a bit more eloquently, but bless Sarah for her aversion to science.

In a fit of frustration, Mark runs out of the barn, where he encounters Gracie’s mom, who — like the midwife — remains devout to the Prolethean cause. She shoots him in the leg, and as he limps off into the corn field, begging for his life and proclaiming his genuine love for Gracie, her mom shoots him in the head. After all the gore earlier with Seth’s body, we’re thankfully spared an actual shot of the, um, headshot.

I have to say, I’m really sad to see Mark go, since he was seemingly the only good-hearted Castor clone. He defied his orders, he rejected his heritage by burning off his tattoo, and he really did love Gracie. He was an okay guy, and now all we have left (for now) is Rudy. I doubt that if there are more Castors, there’s a decent one among them.

One last thing: I just want to express happiness with one little detail. While Helena’s locked up in a cell, we get this shot of her reclining with her arms above her head, and wonder of all wonders, she has armpit hair:

BBC

That’s a great realistic touch. Too often we see women in fictional situations in film and TV where they wouldn’t have access to shaving utensils, and yet their legs and underarms are so perfectly smooth, their hair mussed-up just so, subtle makeup intact. It’s a small touch, but one that speaks to Orphan Black’s mission statement to deliver legitimate female-centric stories with no BS.