Jimmi Simpson Interview with ET 

WARNING: Many spoilers ahead from Sunday night\'s season finale of

finally delivered on several grand reveals -- from Ford\'s (Anthony Hopkins) true intention with his new storyline to Maeve’s (Thandi Newton) absolutely tragic attempt to escape. But while many theories were obsessively poured over by fans on the internet, the most prolific rumor to prove true had to be Jimmi Simpson\'s William putting on the black hat, and revealing himself to be a the Man in Black Ed Harris\' character would later become.

Even though it was a moment many more ardent fans saw coming, the reveal feels all the more weighted by Dolores’ (Evan Rachel Wood) heartbreaking realization of what William had become.

Simpson spoke to ET about the thrilling finale, and that moment in particular, as well as what we might see in 2018 when the breakout HBO series returns for season 2.

MORE: \'Westworld\' Finale -- [SPOILER] Is Wyatt, Maeve Attempts Her Escape and Ford\'s New Narrative Is Finally Revealed

ET: You actually guessed pretty early on that William would become Ed Harris. Did that inform how you played the character?

Jimmi Simpson: Not even close. That was my main objective, to kind of erase that knowledge from any of my execution of William. And it was pretty easy to do, for a couple of reasons. First of all, the look on [creator] Lisa Joy\'s face when I guessed it indicated to me that she would have been so much happier if I didn\'t ... These guys really know what they\'re doing. They\'re giving the actors this gift of not knowing this tragic end to all of them ... Also, I wouldn\'t have been surprised if she was pulling my leg.

What was that like, being in the dark about how big William\'s arc truly was?

It was gorgeous, it just really allowed everybody to only see the scene that they\'re working on. I think it made all of our performances extremely rich.

Now, you won\'t be back next season, correct?

Which probably means we\'ve seen the end of Ben Barnes\' Logan as well -- tied to a horse riding off naked through Westworld.

That was kind of Logan\'s punishment. You just wanna do your own thing, you want to be your own master, well, you can be the master of nowhere, because I\'m gonna run this show now.

Absolutely. And that\'s where we really start to see William becoming the Man in Black. What was it like putting on that black hat for the first time?

I knew it, and Evan knew it, and she had guessed it pretty quickly. But she just as quickly said, \'They wouldn\'t do that to us. That\'s awful.\' The love affair was so beautiful. And we were falling for it, and were both so invested in these characters. When it came time to start to unwind... we felt exactly the same way that all of you guys did. We knew it was coming, it was really sad. And we had to just keep living truthfully, even though our circumstances were getting sadder and darker. Putting on the black hat was both devastating for me to put on, and for Evan to watch me put on. We were just in pieces.

Truly. That one heartbreak, that time when he was just like, \'I was one of many,\' a heart in love doesn\'t give up that quickly. I imagine that for many of the following years, his main aim as he came back was to see if he could find that part of Dolores again. And I imagine it would have taken a whole lot of disappointments to get him to turn into the person he became.

Beyond the Man in Black reveal, is it true that Evan predicted a lot of what was happening before anyone else?

I can say unequivocally that Evan knew more than everybody else at all times. And solely through Sherlock Holmes-ian detective work. When we\'d share rides to and from work, that would be 45 minutes of her explaining to me all of her takes on what was happening. So observant, so clear. I was like, \'Holy s**t, I can barely wrap my mind around William and Dolores, and you\'re predicting what\'s happening with Bernard and Elsie.’ Evan figured out more than anybody else. And quicker.

We were all thick as thieves. Especially Evan and I, and Ben. We would spend a whole lot of time together when we weren\'t working ... we were so used to each other that we just kept hanging out, and talking about

Hours, and hours, and hours, of sitting around Evan\'s campfire in her backyard ... discussing what possibly is happening on the show we\'re all committing our lives to.

I don\'t know. Lisa and [co-creator Jonathan Nolan] are so sweet, but I\'ve described the way they withhold information like loving parents around Christmas. We\'re all speculating on what these next seasons will be based on shows we\'ve seen, based on the arcs of seasons of shows. But Westworld has shown up and basically redefined a television show, in my opinion. So, I would not be surprised if what\'s happening next is both bigger, and more specific and grounded than anything anyone\'s really imagining. I expect them to shock the s**t out of me ... and the obvious next step that I haven\'t even thought of.

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