Henry Winchster (Gil McKinney) has a family discussion with his grandsons, Sam and Dean.

WARNING: Spoilers ahead!  

As if ‘Supernatural’ doesn’t get twisted enough with all that they deal with, eight seasons later, they’ve still managed to add something new to thicken the history of the Winchester family with this latest development in Episode 12, titled “As Time Goes By.”  This time they meet a 20-something version of their grandfather on their dad’s side, Henry Winchester, who happens to know about the supernatural realms, something which they thought was only realized by their dad, John Winchester – at least on that side of the family.  Alas, this brings about a whole new slew in questions, and apparently, we’ll be finding out more in the next episodes.  Executive producer Robert Singer answers some questions about this new revelation and what’s to come for the Winchesters in the next episode.

[Will we] be seeing the secret location housing the knowledge of the Men of Letters?

Bob Singer: The reveal of that place, which I believe is in the next episode, it’s a really stunning set. It’s full of mysteries. It’ll become kind of a home base for the boys. We’re really excited about it. After 8 years of never having a home base, this’ll be home base for quite some time. And I think you guys will really dig the set.

When they go in there, it’s pristine. Like it’s been hermetically sealed. Everything was just as it was, and it’s perfectly neat. The only sign that somebody had to get out of there in a hurry is a chess game that was incomplete and an ashtray full of cigarettes.

To see a clip of boys checking out their new digs from the next episode, “Everybody Hates Hitler,” go here.

What’s in there?

Bob Singer: If you took Dad’s journal and you multiplied that times 100. It’s got every source of information that would be interesting to the boys.

The Men of Letters represent a big twist in the mythology of “Supernatural.”

Bob Singer: It makes you kind of wonder what Dad would’ve been like, which I think the boys say at the end of the episode… I don’t know if you guys remember the Cupid episode, where he said it was ordained that these two people should get together. And now we know who the grandfather on that side was, and why John became why he was in terms of his relationship with the father. It was supposed to be something different. He was supposed to be a Man of Letters but he became a Hunter out of necessity.

Will we be seeing any more of the Men of Letters?

Bob Singer: They’re all gone. The Men of Letters are all gone. The last surviving one was the old guy in the home, and he’s no more.

The casting of Grandpa Winchester (Gil McKinney)

Bob Singer: He came in and read and we just thought this was the right guy for the part. I thought he did a really nice job.

We were just looking for the best actor and the guy we thought would work well with the boys. And also that there was a contrast. You know, this was a guy who was more elegant and more learned and more educated, and our boys are rough-hewn. So when he says, “Hunter…” He was so appalled at that notion and, you know, came around at the end.

Why was Dean so angry with Henry throughout the episode?

Bob Singer: Dean [Jensen Ackles] had a more complicated relationship than Sam [Jared Padalecki] did with John… Dean, I think, was more conflicted about his dad, and it’s been pretty consistent throughout the show that Dean is always in defense of Dad. And John made the ultimate sacrifice for Dean. So I think he takes this stuff a little more personally than Sam does, and that’s kind of what you see in this last episode, it’s reflected there.

via Zap2it.

In another, more extensive interview, we get more answers from Singer about the episode: 

Can you talk about the differences between Henry and his son, John?

Well, John was a product of the fact that he didn’t have a father growing up, as the first of many a bad luck for him. So, he sort of held a grudge against his father because he thought his father deserted them. Now we know different and in retrospect, it makes you sort of wonder what Dad would have been like, which I think the boys say at the end of the episode. We wanted to do it because we had spent time with the other side of the family and just to bring things full circle. Also, I don’t know if you guys remember the Cupid episode where they said this was ordained, that these two people should get together, and now we know who the grandfather on that side was and why John became who he was in terms of his relationship with his father. It was supposed to be something different. [He] was supposed to be a Man of Letters but became a hunter through necessity.

Were there challenges in going back into the Winchester mythology that you weren’t expecting? Did it open up a lot of new doors?

Well, look, we make this stuff up as we go along … [Laughs.] But we try to use what we’ve done before and be able to spin out from there and tell interesting stories and get into backstory like this. Up until the time Adam [Glass] came up with the notion, we hadn’t really explored that side of the family, Grandpa Winchester. But we thought that the idea of it, of harkening back to what Cupid said and how this was all ordained and was top priority [for heaven], it just was a nice closing of that circle for us and also gives us this new home base that’s sort of chalk full of information and will certainly lead to other stories. So, you’ll see that open up next week and it’s cool.

How much of that idea for [hiding] the box [and walking away] might be foreshadowing for the tablets? Are we supposed to think maybe they’re better off not finding and decoding all of these tables?

You guys are always so ahead of us. [Laughs.] This all plays into the tablet business. Again, if Crowley got his hands on the angel tablet and could somehow decipher it, that would be kind of a bad thing. The information that’s contained in this Men of Letters bunker, if it fell into the wrong hands, would be quite a powerful weapon against the boys, so it has to remain a secret and guarded closely. As we go down the line into the rest of this year and hopefully next year, those sort of dramatic turns will take place because this is an important place.

Henry talks a lot about their legacy and their lineage, does this get Sam and Dean thinking about their blood line? Like what happens after they die and there’s no one to carry on all of this?

That’s interesting. I don’t think the boys think that far, to having children of their own. Maybe Sam thought of that earlier in the year before he tragically had to leave Amelia. It may come into play down the line somehow. I don’t think a full-time domestic Sam or a domestic Dean is something that the audience is particularly interested in.

Now that you opened the Winchester can of worms, are there any plans to bring in that side of the family further like you did before with the Campbells?

Not at the moment. But pretty much every year we kind of block out, in very general terms at the beginning of the season, the theme of the season and what we want it to be. Sometimes early on we don’t exactly know where it ends, we just know where we’re going but not how we finish it. That would be a discussion for next year that comes up in the room. I mean basically what’s always happened, whether Eric was there or Sera was there and now Jeremy, is basically the two of us sit in a room for about a week and just kind of throw all kinds of stuff around and then come up with a very loose structure. Then we bring all the rest of the writers in and start filling in the pieces. But we always feel that we want to, like I said, bring that season’s story to a close but open up a new doorway for next year.

You can read the whole interview at HuffPostTV.