After an hour as action-packed as it is revealing, Harris teases a secret motivation for The Man in Black's change of heart in Season 2.

[Editor’s Note: The following article contains spoilers for “Westworld” Season 2, Episode 4, “The Riddle of the Sphinx.”]

During the second season of “Westworld,” Ed Harris’ character, The Man in Black (a.k.a. William), has treated the robotic hosts with much more humanity — well, most of them.

“It depends on who the hosts are,” Harris said in an interview with IndieWire. “He’s buddied up with Lawrence (Clifton Collins Jr.)… so he’s definitely defending him and, as a result, his family. [But] Craddock is a host and so are his henchmen.”

Look what happens to them. In an (ahem) explosive Episode 4, The Man in Black is captured by Jonathan Tucker’s Major Craddock and his goons, only to escape in dramatic fashion and provide his robotic partner-in-crime a chance for revenge. Though the beaten and bloodied Man in Black certainly has reason to blow Craddock to smithereens, he lets Lawrence do it instead — as a gift for what his wife goes through at the hands of the corrupt major and as a sort of wish fulfillment for William himself.

As hinted at earlier and confirmed in “The Riddle of the Sphinx,” William’s wife committed suicide, slitting her wrists in a bathtub. So when he sees the rain dripping off the sides of the roof, a wife being tortured in front of her husband, and a daughter crying in the corner, he can’t help but put himself in Lawrence’s shoes. Speaking to Craddock, William may say the host isn’t his friend, but there’s something different about the Man in Black this season. He’s not so bad.

“It’s so difficult to really explain, but it’s situational,” Harris said. “He’s trying to rectify something that he feels is wrong, so he has to do what he has to do. If that means seeming to care about some of the hosts, then so be it.”

Harris said there’s a revelation coming about William that will provide more context for his actions in Season 2. Sure, the game is real since the hosts have been set free — no longer kept from harming guests like him — but there’s more to it than that.

“He finds out something about the aspect of the park that he was somewhat responsible for, that he finds particularly offensive and personally infuriating,” Harris said. “He decides to do something about that.”

Harris then cited the following quote from Episode 2: “I have received my judgment all the same, and I take issue with it. […] So I’m gonna fight my way back and appeal the verdict. Then I’m gonna burn this whole fuckin’ thing to the ground.”

“That’s because something you find out eventually, during the course of the year,” Harris said.

Of course, viewers found out a bit more about William in Episode 4: His daughter is in the park, and she just reunited with dear ol’ dad. Played by Katja Herbers, the woman previously known as Grace may, in fact, be named Emily. Whatever her name might be, after narrowly escaping being eaten by a loose tiger from The Raj (Delos Destinations’ Park 6, which looks like 1930s colonial India), she resurfaces at the end of Episode 4 and greets Harris’ Man in Black by saying, “Hi, Dad.”

Though Harris is tight-lipped about providing more details for her character, he did know she was going to show up long before the day of the shoot.

“I knew more, prior to the second season, about what was going to happen than I did about the first. That’s for sure,” Harris said. “I pretty much knew the basic arc of what was going on [and] I knew that I’d be meeting up with my daughter at some point.”

Tucker, meanwhile, didn’t even know if he was human or a host. When approached about the role by creators Jonathan Nolan and Lisa Joy (the latter of whom made her directorial debut with Episode 4), Tucker didn’t know anything about who he’d be playing.

“I was dying to go to Sweetwater,” he said. “I just wanted to be in the park.”

Obviously, he got his wish and more. As the villainous Major Craddock, Tucker had aptly important one-on-one scenes with two of the series’ biggest stars: Evan Rachel Wood in Episode 2, “Reunion,” and then a showdown with Harris’ Man in Black this week.

In terms of preparing for Episode 4’s intense back-and-forth with a four-time Oscar-nominee, Tucker said, “That’s your responsibility as an actor, to show up.” Even when it’s Harris’ turn to speak, Tucker said, “You don’t think about it in the moment. […] Driving home is when [it hits you].”

Tucker said the idea of working with someone as professional as Harris is “what brings you into acting, keeps you acting through everything, and [when you get a scene like the one in Episode 4], this is what you think about when you die.”

Even though their last scene together starts with dueling monologues, Tucker insists on giving credit to the entire crew (and especially Joy) for bringing it all together.

“Anyone who looks at the scene as a duet between me and Ed Harris doesn’t understand that it’s a choir; it’s a choir that gives that scene its resonance,” he said.

Neither actor said they think about their characters as protagonists or antagonists. If pushed to pick one, Harris said he’d label the Man in Black the former.

“I see him as a protagonist, especially this season,” he said. “I think what he’s after is morally sound at the moment.”

In the coming weeks, viewers will find out exactly what that means.

“Westworld” airs new episodes Sundays at 9 p.m. ET on HBO.

Sign Up: Stay on top of the latest breaking film and TV news! Sign up for our Email Newsletters here.