WOW! Great debate guys, both Olivant, and Don Cardi make great points. I personally agree with all of them (points). The degree of betrayal will always be debated, however all that was just discussed makes perfect sense, recently wathing "II" again i was focusing on those points in particular and came to a very similar if not the same conclusion about Fredo's involvement. He wanted to take over and believed R&O, whether he "knew" it was gonna be a hit or not will always be debated. i believe he did. He was the only one to access the house comfortably and "open the drapes". Also in a very early scene at Anthony's First Communion reception, when Fredo "apologizes" to Michael about his wife. Notice the expression on Fredo's face when Michael tells him he don'y have to apologize. The expression (on Fredo)is one of "knowing something", "worry"' and almost "guilt" simutaniously. Is that a clue? John Cazale was such a great actor and could show a lot with settle expression! any other thoughts?