For an hour that prominently featured Cosima held captive in a basement, Orphan Black Season 5 Episode 6 was easily one of the show's funniest installments ever.

Of course, that's entirely thanks to the impeccable comedic timing of Tatiana Maslany as Krystal Goderitch (and Tatiana Maslany as Sarah Manning reacting to Krystal Goderitch).

As usual, the main action was split in two, between what's been going on back on the island and what's happening on the mainland.

On the island, all hell broke loose in the aftermath of Yannis' escape, attacks, and eventual death on Orphan Black Season 5 Episode 5.

The villagers were getting antsy because people were dying, and they had no clue what was going on. They'd all showed up for the fountain of youth, and yet Westmoreland's treatments hadn't been successful for anyone.

I have to wonder... How long have these people been there? Why did this not occur to them sooner?

I get that Yannis in the woods was a major wake-up call for them, but are we seriously meant to believe that no one had major doubts about Westmoreland's promises since being on the island?

Things just got hairier when Aisha died. As we'd found out during Westmoreland's epically awkward dinner party, the supposed improvements shown in Aisha's cancer were actually just the cancer being modified by Westmoreland as part of his LIN28A experimentation.

Westmoreland is a selfish bastard and has never been out to help anyone but himself. The reveals about him during this hour made all that emphatically clear.

For one, he is not actually PT Westmoreland at all. He is, as his conversation with Susan confirmed, a man of average age named John. John had enough money to recruit both Susan and Virginia Coady to his team back in the 1960s.

They are the few aware of his true identity and the myth he built around himself to prop up Neolution's ideals.

The other major revelation is that the treatments Mud was assisting Westmoreland with were actually blood transfusions – Westmoreland was having the blood of innocent kids injected into his own body.

That reveal, paired with her discomfort over the whole Kira Manning experiment, led Susan to finally break away from Westmoreland once and for all. Via Ira, she recruited Cosima and Mud in an escape plan, intending to kill Westmoreland during his latest treatment on her way out.

Unfortunately, revelations about Mud's past made it clear that this daring escape would not go as planned at all.

In the course of Cosima attempting to convince Mud to help out the team, Mud revealed the cause of her allegiance to Westmoreland – apparently, she'd been a junkie and he had saved her life. Not only that, Revival had effectively given her a place to call home and something to live for.

I was honestly shocked that Mud went along with the plan as far as she did, allowing Susan to inject some toxic substance into the IV bag when Westmoreland was getting his transfusion.

But it was not at all surprising when Virginia Coady busted in, guns a-blazin' and trailed by a sheepish Mud, to save Westmoreland from Susan.

Virginia [to PT Westmoreland]: She was trying to kill you.
Susan: No. I was trying to save us all.

• Permalink: No. I was trying to save us all.

That said, the entire closing island sequence was incredibly well-paced, tense, and exciting. Especially Susan's Wordsworth monologue voiceover as the village burned.

I was holding my breath almost the entire time, hoping that Cosima and Charlotte would make it off the island.

(OK, confession time: I had completely forgotten all about Charlotte. But I'm glad she's okay!)

As creepy as I've always found the Susan/Ira relationship (which has always uncomfortably bordered the maternal and the romantic), their final scene was heartbreaking. It made perfect sense that a glitching Ira would accept his fate and remain behind with his beloved Susan.

That final scene of the two of them was a gorgeous tableau.

Or at least I'm assuming it's their final scene, though we didn't technically see that Ira was dead.

Back on the mainland, Sarah & Co. got a visit from a familiar face: Krystal Goderitch.

I've always absolutely adored Krystal. She was a fantastic comic relief character throughout the almost-unrelentingly dark Orphan Black Season 4.

She was used to her absolute best during this hour.

As much as I was looking forward to seeing Sarah do an extended impression of Krystal, Krystal interrogating Blue Zone Cosmetics' owner Len was even better than I could have imagined.

She's been poisoned. By Big Cosmetics. What about that is confusing?

Krystal

• Permalink: She's been poisoned. By Big Cosmetics. What about that is confusing?

Once again, Krystal can't possibly comprehend the entire clone saga. So, as far as she knows, this whole debacle is just yet another instance of "Big Cosmetics" (her take on "Big Pharma") attempting to take her down for her vlogging.

The fact that Krystal knows nothing and yet repeatedly stumbles into incredibly important information continues to be hilarious.

This time, her funny "interrogation"/seduction of Len led to the reveal that Neolution (via Dyad) has acquired a cosmetics company in order to develop a product for dermal delivery of some kind of gene therapy – yet another step in their overall plot to "improve" the human race (with the human race likes it or not).

That reveal was terrifying, and crystallizes just how badly Neolution needs to be taken down once and for all. Their reach is on the verge of spreading far and wide, beyond anyone's control.

Krystal's freakout and take down of Len was absolutely amazing and badass. Don't call that gal stupid! Her rubbing the cream on Len's beard as "revenge" was a perfect touch, as were her literal kicks to his ass.

Finally, the hour ended with Rachel arriving to take Kira away to initiate her hormone treatments – which indicates that the remainder of the season will be an extended rescue mission.

Now that Rachel has Kira and the experiments can begin, I doubt she will give her up now. At least, not without a fight.

Stray thoughts:

• I enjoyed Krystal's return, but I still really miss Felix and Alison! It's a serious bummer that they're gone for so much of the season.

• Could Frontenac be Siobhan's second source within Neolution? I'm actually starting to think it might be someone we'd never expect....

• Perhaps it might even be Rachel. Can you imagine that reveal, if it turns out Rachel was deep undercover this entire season? That would be bonkers.

• Speaking of Rachel: how is she going to feel about what Westmoreland and Coady did to her mother? Sure, she was on the outs with Susan, but will she care that she's dead?

• Maybe it's just because I only want happiness for Scott, but I'm already kind of rooting for him and Brie even though we know nothing about her.

• Virginia attempting to convince Cosima to come over to the "dark side" was super spooky. But never in a million years would that speech have worked on Cos.

What did you think of "Manacled Slim Wrists"? Share your thoughts by commenting below, and don't forget that you can watch Orphan Black online here at TV Fanatic anytime!

Caralynn Lippo is a staff writer for TV Fanatic. Follow her on Twitter.