The last scene of last season’s Dexter was such a shocker that I thought maybe Showtime was going to have that be the end. But here we are talking about Dexter again. The new season starts in late September and appears to pick right where they left off. Will Dexter finally get what’s coming to him? Or will he continue to deal out vigilante justice while being a single Dad? The normal formula is that Dexter runs across another serial killer and somehow becomes involved with him, as brother, mentor, or student. I think Harrison is a little young to…