For most filmmakers, getting audiences to come out to see their latest work is always a battle, but in the case of “The Strange Ones,” Lauren Wolkstein and Christopher Radcliff have faced a more enviable one – getting them to leave after a screening’s over, not that they necessarily want them to.

“Audiences have been responding to it in a way [where] it’s not just they’re going to see the movie and walking away from it with all the answers, but it actually provokes them to ask questions in a way that’s satisfying to them,” says Wolkstein, of the enigmatic thriller’s hold on people that has led to marathon post-screening Q & As. “That’s one of the reasons Chris and I made this movie was because we love movies that are discussed long after they’ve faded to black and it’s been exciting for us to see that same reaction out of people that were watching our movie.”

Although “The Strange Ones” marks Radcliff and Wolkstein’s feature debut, it arrives after the pair separately established themselves as directors with captivating shorts, such as her “Social Butterfly” and his “Jonathan’s Chest,” that festival programmers would want to close out a screening with since showing them at the start might not give audiences a chance to think about anything else. As it turns out, the pair couldn’t actually stop considering the possibilities with a short they made together in 2010 about a twentysomething man and his younger brother whose stop at a roadside motel reveals unexpected fissures in their relationship as they have different memories – and different understandings, based on their age – about a traumatic incident in the past.

“The Strange Ones,” the expansion of that short with the same name, proves to be every bit as seductive as their previous work, joining brothers Nick (Alex Pettyfer) and Sam (James Jackson-Freedson) on the road to an unknown destination, running from a past that initially is only slightly more spelled out. Over the course of their travels, the focus on the source of their discontent sharpens like a knife, which is fitting since the film feels more dangerous the more you know since what you don’t becomes deeply unsettling. Once they have your full concentration, Radcliff and Wolkstein shrewdly draw out small environmental peculiarities sonically and visually that so often act as details in memory to create a rich sensory experience that enraptures without ever putting one at ease, resulting in an edge-of-your-seat potboiler.

Following a premiere earlier this year at SXSW, “The Strange Ones” has been a conversation starter the world over, including talk of awards as the end of the year honors approach and with the film screening in advance of its theatrical run in January, most notably at this weekend’s Vulture Festival in Los Angeles, Wolkstein graciously hopped on the phone to discuss her collaboration with Radcliff, making the leap to a feature while keeping the mystery alive and the importance of rigorous preparation.

James Freedson-Jackson in "The Strange Ones"When did the idea for a feature come? Was it actually something you thought about while making the short?

We were not actually thinking of making a feature when we made the short. Chris and I both went to Columbia for film school together and we decided to team up on making this short film. It was our last year in film school, and we had both made our thesis films prior to that, but we weren’t ready to be finished making shorts. We both loved the short form of filmmaking, so we wanted to team up and collaborate on a project and we didn’t have a lot of money to make it, so we wanted to create some limitations for ourselves. We decided to make a story about three characters in one location, centered around a bit of a mystery, and we wanted to create an atmosphere more so than really following any one character.

It was really after [the short] started playing at several different festivals and we were getting feedback on it that we decided that we weren’t finished with that story – the short is only the motel sequence in the feature – and we wanted to continue the journey and show who these characters were and where they were going. We had done a lot of research [for the short] about several different true crimes and when we decided to expand that into a feature, we wanted to keep moving forward and developing a feature based off of who these characters were, what they were running from, what is the true nature of their relationship, but keeping that mystery alive in the feature and that was a big challenge for us.

You and Chris have said before that you had to give up some of the mystique upfront in a feature to keep the audience invested, which may seem counterintuitive since you have more time to work with, but how do you figure out what to give away earlier while still keeping certain things elusive?

That was the challenge throughout making the feature. Chris and I [had to] think about when we’re revealing information and why we’re revealing information about the past and not have it come across as just exposition and background, so [in the feature], it was more thinking about the subjective experience of the kid in the feature, really going through his journey and his own processing of what’s been happening in his past and how he’s going to survive his present. His memory is very fractured and abstract in a way that a survivor of trauma would remember an incident like that – he’s not able to process it all – so when we did reveal moments in his past is based on when we’re trying to show his experience and keeping it within his experience and not just thinking of them as flashbacks.

Alex Pettyfer in "The Strange Ones"How do you and Chris co-direct? Were there certain responsibilities one of you would take the lead on?

It’s a good question and we get asked it a lot and I think it’s because you don’t see many co-directors that aren’t siblings or married, but Chris and I share the same language, going to the same film program, and share the same sensibilities. We never really wanted to divvy up any roles when directing because we love directing so much – working with actors, with the camera and all the [other] responsibilities that come with directing – when we work together, and I actually think it’s a great way to work even if you’re solo directing, is to do so much prep work.

We had several months of prep where we would be shotlisting every day with our [cinematographer Todd Banhazl] and figuring out the schedule with our [assistant director] how much time we actually have for shots, where exactly we’re going to be setting up the camera and what each scene needed beat by beat. By doing that groundwork early on and previsualizing the whole movie before we were shooting it, we could just focus on our actors since we had that shorthand. We had a huge previsualization document, and [because] it is a movie that has a form that’s very specific, when we were on set, if one of us had a note to give an actor, we would just give that note and if the other one of us wanted to do something different or wanted a different adjustment, we’d just do another take, so that we’d have those alternates. It wasn’t a matter of any huge discussion behind the scenes because any time you’re not shooting, you’re wasting time.

How did James and Alex come onto this as your leads?

We got really lucky with those two. We have a casting director, Jessica Daniels, who’s really brilliant, who we’ve worked with on all of our movies and she brought James Freedson- Jackson into the casting session. He just really blew us away. We hadn’t really seen a kid with that much intelligence and really understood the material in every sense of the word. He was able to show without indicating too much with his face, like you could tell that he was processing a lot of information under his eyes. That was really exciting to see because right away, he got the material very organically and blew us away with the maturity that he had.

Then Alex was one of the first people that came on. He really responded to the material and had so many great ideas about the character. Because I think it’s going against the usual roles that he played before, he really wanting to dig into these other sides of himself that he may not have been able to perform in these other roles. Once we cast Alex, we did a chemistry read with him and James and they got along so well we knew right away that they had this brotherly bond that was really special. That’s when we knew they were our two leads.

After the casting, we’re there any bonding exercises to help foster that brotherly bond?

Yeah, once they were cast, we had them going out together for a couple days and we gave them a few exercises where we told them to do certain activities together, but tell us what those activities were and have one of them be a lie – this elaborate lie that they tell us – but not to tell us which one was the lie and we’d have to guess. And I still don’t know to this day if we know the truth of what really happened. [laughs] That was really helpful because they had secrets, as well as lies, that they kept to themselves and had this special bond that nobody else shared with them, and that was really important as a part of the fabric of the movie as well.

Since you describe it as fabric, you really do create all these layers in the film, one of which is the diegetic sound that really immerses one in the environment and pulls you in with a certain rhythm that begins to take shape. Was there special attention paid to capturing that element of the film while on set?

Yeah, the sound design was a huge part of the atmosphere for us. When we think about heightening the experience of what you see, it always relates back to Sam’s perspective and before we went out to shoot, we did think about making sure that we could get good enough production sound so that we could manipulate it in post and create this kind of suspenseful experience for the audience that goes along with Sam’s experience in the woods, in nature, with the fire, kind of building that tension with sound and this heightened sense of anxiety. Creating that mystery with the sound was really important to us, so we definitely thought about when to heighten the sound, when to take the sound out, and throughout the [post-production of the] movie, we did passes for the sound specifically in terms of how the audience experiences it to create a subjective experience through these different parts on his journey, [where he] goes into the unknown and not really knowing where he is.

Alex Pettyfer and James Freedson-Jackson in "The Strange Ones"Is it true there were certain anamorphic lenses you used to build in layers visually?

Yeah, we wanted to use these anamorphic lenses to create this feeling like that there’s this large land that they’re surrounded by and the world is opening up to them, like it feels like they’re in the middle of nowhere and we’re showing all these sides of nature and anamorphic lenses really opened it up to show that expansion of the land. We used a lot of new lenses and a lot of really old vintage glass to create that layering effect and this sense of boundaries. Shooting through layers of glass, [we could] give the audience something to lean into, to feel like they’re focusing in on something that there’s different barriers to look past and to question what they’re actually seeing. The anamorphic lenses really bring out the effect that what you’re seeing is much bigger than what you’re showing and [asks the audience] if what they’re actually seeing is everything, or we’re hiding something from them.

Having mastered the short form, was making a feature any different?

The biggest challenge was expanding this ambiguity between these characters that worked so well in the short and really creating a feature-length film where almost every scene feels we’re answering a few questions, but then we’re giving more questions out and trying to think about the audience’s experience of the film and not wanting to make them feel like they’re lost. What was difficult – and very important for us – was to provide multiple interpretations for each scene so that it could be viewed one way or another, depending on which path you’re choosing to look in terms of who these characters are to each other and crafting the film in such a way that we’re providing that question of what’s true and what’s not true.

That was really challenging and ambitious to do in a feature-length film, but after spending so many years on this material, I think Chris and I really found a way to strike that balance, of keeping it very nuanced and not giving away too much information [to the point] where we feel like we’re spoonfeeding an audience. Ultimately, it ended up being what Chris and I set out to do – creating this sense of mystery in the film that we think works.

“The Strange Ones” will next play a free screening in Los Angeles at the Vulture Festival on November 18th at 5 pm at the Hollywood Roosevelt Hotel. Tickets are available here. It will be available exclusively on DirecTV starting December 7th and in theaters on January 5th.