If u are playing a good character then destroy it.. The Dark brotherhood is a group of men who kill for money, i wouldn't call them "good" or "neutral"

Well you do see the black sacrament, a ritual that is performed using human flesh and bones, which you can clearly see from the room he's in, which also has a kiss, sweet mother, or whatever book it is, which provides some information on the dark brotherhood. But besides that, guess you're right.

Double post

Acutally Drasanil there IS a good guy option: the OP could follow their conscience and opt out of the DB entirely. Although I'm not entirely certain what happens if you opt out of completing the assasination contracts after a while. That scenario never happened to me because my Battlemage was a walking sociopath It's times like this when I long for the dark certainties of TES centuries past. It was particuarly entertianing after getting expelled from the DB for breaking the tenets. I miss having to suffer the bloodthirsty wrath of Sithis stalking your character after they succombed from chronic insomnia.

Actually, it's a bit more than that. Money motivates the TG. The DB however kills for the pleasure of killing. This is particularly true of the more "spiritual" DB members (eg Cierco and Gabriella) who believe in the divine power of Sithis. Unlike Arnbjorn or Nazir who are more cynical of the Night Mother's ability to communicate with the Listener. So these DB members tend to put more faith in following a mortal leader like Astrid.