I seem to have gotten stuck. I'm in the PentHouse level, where you only get a pistol, and if you're seen or heard, you lose. I can't seem to get anywhere (literally, I'm usually dead within 30 seconds to a minute of the level starting).
If I try to sneak past the guys in the living room and kitchen, I'm seen. But if I wait for people to move around, a guy either comes down the stairs and sees me, or a guy just inside the penthouse sees me. I can't gas them either, even though I've got gas grenades and the mask to do so.
Anyone have any pointers they can provide? I've gotten this far, but I can't get any farther and it's killing me. Thanks!