Hauser's Johns continues the Pitch Black trend of complicated individuals who are rarely what they seem, a theme he is all too familiar with. "I want to play the people that really leave some kind of mark in your head," says the actor, whose credits include a string of unsympathetic characters in films such as Good Will Hunting and Higher Learning. "When I was starting out, I played a skinhead, and that one was hard to get away from. Everyone wanted to hire me as the bad guy, the skinhead, the racist or whatever, but in reality I'm a Russian Jew. I'm not really a skinhead -- give me a fucking break!"

Hauser describes what attracted him to the role of Johns in particular. "He's charming, he's evil," he says thoughtfully. "He's a drug addict. I think as an actor, you dream of playing a whole bunch of different roles within a role and that's what Johns is, he's a whole bunch of different people." It was one particular aspect of his character that led Hauser to give one of the movie's most memorable scenes -- addict Johns injecting a lethal narcotic through his eyeball -- a disturbing sense of realism. "Everyone was against it," he recalls fondly. "The producers, everybody, just because I could have missed my tearduct and stuck my eye, which I actually did once.

"I was talking to this guy who had done heroin for 20 years or something like that," he continues. "And he goes, 'I'll tell you this story about this guy. This friend of mine, when I was doing drugs, he used up so much of his arms, his toe, all these things and he came up with shooting up in his eye.' I was like, 'What?' and he was like, 'Yeah, he took the needle, and he'd take his tearduct, and stick the needle in there, and pump the heroin in his eye.' And I thought, 'I have to bring that to David Twohy. That's a good idea.' It's something you've never seen in film, I don't think anyone's ever done in film. The idea is supposed to make you go uggghhh," says Hauser, shuddering and making a face. "And I think it does that. Right? David was going, 'Left a little bit, right a little bit, OK, go down,' because it had to be a perfect incision."

Hauser, whose interest in acting came in part due to the influence of his father, actor Wings Hauser, found green screen work -- the method of shooting in a film in which computer-generated elements, in this case the film's alien creatures, are later added -- a particularly difficult aspect of production. "Green screen was a real, real challenge," he says. "Just a challenge to your acting ability to be able to create a picture in your mind without anything there to react to at all. I look forward to doing more, in a funny way, because it really challenges you as an actor. People can walk down the street and have things to react to, but green screen is like you're a child again."

Also memorable for Hauser was a fight scene with co-star Diesel. "He's big, but I'm fast," laughs the star when asked if the battle was mismatched. "The fight scene was great. There was a couple of times when I'm down on the ground and I'm trying to stick a knife, and I'm putting all my weight on this guy, 180 pounds or so, and he's just sitting there like that." Hauser assumes a position of stoic nonchalance. "I was thinking, 'This ain't easy.' He's a strong guy. The thing is, you don't want to get in a wrestling match with him, you get in there and then bang bang you get out!"

A far cry from the often tempestuous characters played by Diesel and Hauser is that of Imam, a Muslim cleric played by veteran actor Keith David. "He is the spiritual backbone of the piece," explains David, whose past work includes dozens of film roles as well as numerous theater credits, including a Tony-nominated performance for the musical Jelly's Last Jam. "One of the things that the piece addresses is man's duality, good side versus evil, and how faith and spirit play in that duality. His journey is to have his faith tested, to stay within it and then lose it. You have the extremities of his testing."

Much of David's preparation for the role involved an intensive examination of the culture of his character. "When I accepted the part, I began to read up on Islam. At one point in my life I studied Sufism, which is the sacred form of Islam, so I knew some things, philosophically. But then I began to get more specific about it." Among the specifics was a crash-course in Arabic. "I was asked if I wanted to make an ad-lib, and I would want to say something but I didn't want to speak English. If you speak English as a second language, when you get in trouble, you run back to your first language," he points out. "You think in your own language and then translate it back."

A classically trained graduate of the Juilliard School, David is best known for his roles in horror fare such as John Carpenter's They Live and The Thing. "I like to work," he dead-pans, when asked about his relationship to the genre. "Ask me, I might. Thank God for my training, I feel like I can embrace different genres. You go with it, you know? But I particularly do like science fiction, because it involves an engagement of your imagination that you don't have in a straight drama. You explore a new world, and it's different than the occult which also addresses a different belief system, a different set of paradigms. It's fun, it's cool playing it, it's great." However, his ideal role is a far cry from his current character. "Nat King Cole," he says, drawing out the words. "I'd love to play Nat King Cole."