They smoke and drink and talk and laugh, like ordinary people, but we know that they are not. We know that they have to die, and we wish that they didn’t, but we know that they have to die. Evil brings doom, no only to the good, but also its followers. And evil is concrete, ambiguous, that’s why each and every one of us should always keep watch.
To me, the "Silence" refers to the vast, encompassing environs - a thick wall surrounding the three, making no room for them to communicate. All three represent the self -- Anna the hedonistic, Esther the Catholic (the guilted, the conscientious), Johan the observant.