Heh, this is the first time I've been invited into the Brotherhood on account of a friendly fire accident. That guardsman and I were fighting a stunted scamp in that first Oblivion gate, and I wound up for a power attack with my iron hammer. I did not hit the Scamp, and the next thing I know, I've got that message about being observed. So here's Lucian Lechance, approaching me in the ruined Chapel of Akatosh in Kvatch. Heh.
I'm trying to remember if I've ever had a character who did the main quest without being invited into the DB. Those stupid Imperial Guards who join you in clearing the last of the Daedra out of Kvatch are suicidal and invariably throw themselves in front of me. :flamethrower: