Small bottle towards the end
I just saw this movie at Film Forum in NYC a week ago and I noticed something I hadn't when I had watched it on DVD. Towards the end of the movie, Barrett procures a small bottle of liquor for Tony that he infers is only available from, as I recall, a German dealer (black market?). I was wondering if it was meant to be Absinthe. After that, Tony takes another downward turn so I'm assuming that it was something very potent and borderline illegal. BTW, alchohol doesn't play as large a role in the book, where believe it or not, Barrett is portrayed in an even more sinister light than the film.