Dan Stevens shocked his many fans on “Downton Abbey” when his character, Matthew Crawley, was suddenly—and irrevocably—killed in a car crash. They may be equally surprised by his performance as David, the mysterious soldier who wheedles his way into a grieving American family with unexpected consequences, in “The Guest,” director Adam Wingard and screenwriter Simon Barrett’s follow-up to their home-invasion shocker “You’re Next,” a recent favorite among genre fans.

“He’s not just a creepy guy,” Stevens insisted during a recent Dallas interview. “That’s really one of the biggest things to feel about this role. We wanted to play with the audience a bit, and I certainly grew up loving those kind of movies that tease an audience and kind of take you for a ride. From the opening scenes you feel you’re in good hands and willing to be taken where these crazy filmmakers want to take you.

“So we wanted to give a certain charm to the character that gets him in the door, that ingratiates him to a number of the family members, but also have a creepy element to him, where the audience would keep asking the question of how they feel about him—the hero/villain thing goes out the window, really. How far can we stretch their sympathies for a character that’s seemingly good but does some quite nasty things? There is something off about him, and Adam and I were keen to explore what happens when you put a character like that…in there, and see what happens. That’s where the fun of the film comes from.”

David sports a slight Southern drawl, and the British Stevens enjoyed taking it on. “Accents and voices are something I’ve always loved doing,” he said, “and it’s been great in the last couple years…playing more Americans. It’s a great privilege to get to come to another country and be embraced in those roles. The Kentucky was an interesting one. People do say that the Southern accent is easier for Brits than some of the others. I don’t know if that’s true, but I certainly took to it well. I have a great friend who’s from Kentucky, whom I got to read the Gettysburg Address to me so that I had all the sounds, the consonants and vowels. I loosely based it on him—David says he’s from Louisville. I’m not sure if we believe him, but we wanted to believe as much as possible that came out of his mouth. So we took a Louisville accent, put it through a couple of different shakes, and I also ran it through a military dialect. Anyone who’s ever been in the military, your accent is modified to a certain extent. That slightly blurs the background of his character, which we sort of wanted.”

Stevens also went through some rigorous training for the past. “The physical preparation was a big part of it,” he recalled. “The psychology that’s required, and particularly the discipline of the martial arts—two hours in the gym every day, two hours of martial arts training in the same facility, and then we’d go to the gun range at lunchtime, and everything in between—represented a lot of new challenges for me. The martial arts discipline was particularly key in terms of dialing in a certain kind of stillness, a certain kind of calm and a certain way of thought that some soldiers definitely have.”

Asked if he enjoyed the big action scenes, Stevens replied, “Yeah, very much. Wouldn’t you? One of the really delightful things about taking on this whole project was meeting Adam and Simon, who clearly love movies and are steeped in cinema. But also, Adam grew up in Alabama and I grew up in Britain, and yet we watched almost exactly the same movies growing up. We were inundated with American action thrillers in the eighties and nineties in England, and I grew up on those things—the John Carpenter movies—‘Big Trouble in Little China’ with Kurt Russell was a big meeting point for Adam and me. If I meet anybody who likes that movie, it’s a fairly high chance we’re going to get on.

“But with Adam, the list went on and on, the ‘Halloween’ movies, the ‘Terminator’ movies. He made me go and watch ‘Teerminator 1 and 2’ back to back—I’d seen them both, but never in one sitting. [We shared] the sense of humor that comes from knowing those kinds of films and knowing the fun that someone like Kurt Russell had with that role—Uma Thurman in ‘Kill Bill’ was another that came up, somebody who looks like they’re having such a good time—and just playing with the conventions of those kinds of genres, playing with the audience’s memories of those genres.

“As soon as people know that they have permission to laugh at a film like this, that’s a good thing,” Stevens said. “We take audiences down a kind of ridiculous path in terms of going between [the comedy elements and the dark, twisted ones]. That was the line we wanted to dance. I hadn’t met Adam and Simon, but when I saw ‘You’re Next’ I met Adam very briefly—I’d just read ‘The Guest’ and thought it was a hilarious script—but ‘You’re Next’ has a very similar thing. You think you know this world, and they just sort of tip you up and then tip you back again, and by the end you know that you’re in this ridiculous world that all of this carnage and this gore has led up to…to me, that just spoke of a deliciously dark sense of humor. When I met Simon, I could see that was not an accident—that’s his sense of humor. And I thought there was a lot of fun to be had with the action thriller genre, sending someone in who’s supposed to be there to help, and he wreaks destruction.

“That’s very funny, but also pertinent to a lot of global political situations,” he added.

Wingard and Barrett, who arrived for a separate interview, discussed whether “The Guest” revealed sufficient details for viewers to figure out precisely why things were happening as they did, Barrett noted that there was originally more information, but some of it was cut after hearing how audiences reacted. “You get just enough to know that we’re not just making it up,” Barrett said. “There is some ambiguity and there are some questions left unanswered in ‘The Guest,’ but there’s enough information that you can kind of answer those questions on your own and come up with your own theories.”

“And that’s the fun of David,” Wingard interjected. “That’s why we’re always doing these push-in shots of him, because we want you to project your own idea of what’s going on in his head. We never really know if he’s a good guy or a bad guy, if the stories that he’s telling are true or not. We have our own ideas. But it doesn’t really matter. Sometimes when filmmakers say it’s up to the audience to figure it out—“

“…it’s lazy storytelling,” Barrett broke in.

“—it’s just a cop-out,” Wingard continued. “But sometimes it’s true. Sometimes that is the point of the character, not to really know. And the point of this character was not to know if he’s good or bad, it’s just to enjoy what’s going on with him, what he’s doing, and kind of throw out the idea of hero or villain.”

Stevens, Wingard added, was ideal for the part. “I wanted an actor who was believable in infiltrating this family very quickly, gain their trust. That was also the fun of casting somebody who’s not known in this genre.”

Barrett said, “To me the creepiness is somewhat on the page, in the character’s actions. What we needed was an actor who could sell the charm. What we needed was an actor who’d be likable, and that was the one thing the actor needed to bring. We started at the charm, and then worked our way back to the creepy. Charm is a much more subtle thing, and Dan Stevens has it in wheelbarrows. He’s not lacking in personal charisma.”

“The Guest” represented a distinct step up for Wingard and Barrett in terms of the physical production. After the success of the micro-budgeted “You’re Next,” Wingard said, “We were in a position where now we could afford—I wouldn’t say professional actors in the sense that they’re better actors than the ones we worked with before, but people who actually do acting for a living. A lot of our earlier films are very improvisation heavy, because that’s the best way to get a performance out of non-actors. “

“As a non-professional actor myself,” Barrett interjected, “it’s harder to do scripted dialogue than just to come up with something that’s how you speak.”

A bigger budget also meant more equipment. “When you have more money to use, there’s a lot more responsibility with that,” Wingard said. “As a director, when you have more access to more tools, you have to think very clearly—‘Am I putting a crane shot here because it’s cool, or am I using it because it fits with the movie?’ You don’t want the movie to look cheaper than your budget, but you want the tools to be used for the right reasons.”

Barrett added, “Adam has mastered the hand-held style, but he didn’t think that was right for this project, so he learned a new visual style.”

It was noted that both “You’re Next” and “The Guest” feature major tonal shifts as they progress. “I don’t know that we’ll always do that, the tonal turn thing that is part for both [those films]. But personally, I know I’m most entertained by films that I can’t totally predict what’s coming next. And I think Adam feels the same way, and I think that’s an experience we like to try to bring to our audience. Too often I feel that when I go to see a movie, I can’t enjoy it because I’m so actively being insulted by it….. ‘I knew you were going there ninety minutes ago.’ So we really do like to bring that sense of fun [to the experience].”

Barrett also praised their producers, Keith and Jess Calder. “We share a unique creative sensibility with [them],” he said. “They afford us the opportunity to do these different things, while still doing films that are hopefully entertaining and delivering what you want from a genre, while also kind of subverting that.

“That’s the kind of films we love the most, and therefore we try to make them.”

Wingard added, “It’s not like we’re necessarily doing anything you haven’t seen before. But it’s almost like we’re taking a different perspective on it…. Simon actually starts the movie as though the movie’s already half-way over and we’re just picking it up. What that does is to create a whole different aesthetic. If we’d have seen where David had come from, your impression of him early on would we different, even though we didn’t try to hide the fact that there’s something ominous about the guy. Having that kind of perspective shift, I think, is what makes Simon’s scripts unique.”

“You have a certain degree of cinematic shorthand,” Barrett said. “We know what other films have done, so let’s skip that stuff and assume that the audience is also smart enough to skip that stuff. We try to make films for people that are, ideally, smarter than us. If you have that kind of respect for your hypothetical audience, you’re at least on the right track. That’s the goal.”