The director, Moisés Kaufman, just received the national medal of the arts from President [Barack] Obama . He wrote and directed The Laramie Project and he has directed several Pulitzer prize-winning plays. He's a pretty profound director in the theater.

I had just come off of doing a play in Los Angeles which actually got me the role. It was called Bent and it was at the Mark Taper Forum. I was playing a homosexual in 1930 to 1934 Berlin who is eventually put into a concentration camp for the second half of the play. I had lost about 38 pounds for that.

I had done a little bit one other time. This character [in Jack Reacher] is a psychopath, but I had been hired by Carlton Cuse and Randall Wallace.

I only had a three-week break from the beginning of Bent, so I went from one thing to the next. I got back [from shooting Jack Reacher] and there was a sense of, "Oh my God, what do I do now?" I don't have personal trainers around me all the time, I'm not on a meal plan, which I had been on for almost a year straight. There was a lot of sleeping.

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'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 was eating with the help of a nutritionist so I was definitely putting in the appropriate calories and vitamins and minerals into my body; however, it was still so little that if I had the tiniest piece of sugar, my brain would go crazy. If I had some alcohol during the run of that play, my brain would go crazy.