I’m still trying to process just what went down on Supernatural Season 10 Episode 21.

I was certainly intrigued by the start of the hour, immediately recognizing that Styne tattoo on the arm, and I kept wondering just what was up with the family.

Harvesting eyes? Super jumps from three stories? Is this family full of Terminators?

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But to discover that their true last name was Frankenstein was a cool twist. I don’t think that the family had to be so massively global or that they were involved with a good majority of major catastrophes, etc. They could work just as well on a smaller scale, but I think they were a creepy and scary group of bad guys, especially when they started losing body parts.

That look from Dean alone after seeing the one Frankenstein member’s arm dangling was both humorous and telling of the danger this new foe brings. It makes me curious to know about the hierarchy and some more about the harvesting to make them like super soldiers.

At the same time, Sam was recruiting Castiel and Charlie into his plan with Rowena to try and speed up the process to finding the code to the code for the Book of the Damned to get rid of the Mark of Cain on Dean.

And I was glad to hear both Charlie and Castiel point out that not telling Dean just seemed like a really bad idea. I, and probably plenty of viewers, were nodding in agreement.

Things were going to blow up and not end well.

I was even a bit surprised that with Sam’s disappearances and the constant phone calls that Dean wasn’t figuring it out. But I also understood that there was no reason for him to suspect something, and the two were also focused on the Styne case.

But as the hour went on, I started to feel like nothing was going to happen until the very end. Like maybe Charlie discovers there’s another code to the code to the code, or Dean finally figures out Sam’s been keeping secrets.

I was even a little bored of Castiel trying to be referee as Rowena and Charlie seemed to get nowhere.

Except, things started picking up after Dean learned all about the Frankenstein family and that the Book of the Damned can’t be destroyed.

Just seeing him stand behind Sam questioning him, pretty much knowing now that Sam was lying to him was rather intense.

But it was Castiel’s phone call that Charlie had disappeared that really escalated everything up a notch.

That’s when I could feel in my gut that Charlie was not going to make it past this episode.

The tension was definitely high with the Frankenstein duo trying to break down the door to the hotel to get at Charlie, hearing Charlie talk to Sam on the phone, listing to Dean angry at Sam for keeping him in the dark and keeping the Book of the Damned.

I was hoping the two would be able to make it, though I knew they probably wouldn't.

It was so disheartening seeing Sam and Dean's look of horror and then seeing Charlie's bloody body in the bathtub. I was frustrated and sad in those closing moments.

Frustrated at Sam for not just telling Dean in the first place and dealing with his anger about it then. Frustrated that Castiel wasn’t paying attention. Frustrated that Charlie ran out of the safe location.

I understand where Sam came from in bringing in Charlie and Castiel, and hearing him exclaim to his brother that they all love him exemplified that. He had good intentions, but we all know how that road is paved.

We all knew there were going to be consequences, and unfortunately for Charlie, the Frankenstein family is ruthless and determined to get that book.

She certainly made a sacrifice for Dean in not giving up her notes and work, and her friendship and loyalty to the Winchesters can never be taken away.

Yet, I still can’t help but feel like her death wasn’t necessary but more of a device to push Dean and even Sam to their respective edges. Plus, I still feel like there was so much more to Charlie’s story considering she’s been growing as a hunter and member of their team.

It makes me worried for Castiel now…

I liked this episode from the furthering of the Styne family to the intense and heart-pounding final moments to the excellent acting from the cast, but Charlie’s death is a rather sour note and it’s going to take some time before that sting goes away.

What did you think of the Styne family's history? Were you shocked by Charlie's death? Sound off below. And if you're already missing Charlie like I am, you can catch any of her previous adventures when you watch Supernatural online.

Sean McKenna was a TV Fanatic Staff Writer. He retired in May of 2017. Follow him on Twitter.