I'm not a method actor but it certainly does help to have that kind of dedication. I treated my preparation like I was in the military. I didn't go out ever. I went out for drinks probably twice in five months. I lived very monastically.

I went into very deep research as to what exactly that meant and how sociopaths function psychologically and within the world.

I had heard that Tom [Cruise] was the same way, that he is incredibly dedicated. I was very excited to meet him and I was, honest to God, weirdly surprised that the guy makes me look lazy. I think he does think I'm a hard worker, but he makes me look like I'm doing nothing. The guy is at the gym before anybody in the morning.

My character is called The Hunter. He's the main antagonist in the movie. In a nutshell, he's a slightly deranged natural born killer who's weirdly determined to succeed at his job, whatever his employment is. He's a mercenary and there's a high body count for him in this film [Never Go Back].

I'm a trained actor and I can always tone it down, I can always simplify the work I've done. But if I'm asked to bring the nuanced and complicated work, I'll have it in my pocket, and all that information helps.

I read as many books about the psychology of a psychopath as I could and I researched what exactly happens to soldiers.

Sociopaths are more complicated psychopaths; the difference between a sociopath and a psychopath is a sociopath is incredibly charming. There are a lot of sociopaths that are CEOs. They don't necessarily kill people but they're able to walk into a big social function and make everybody think they're the kindest, coolest, smartest, most interesting person in the room.