I got Dawnguard for the PC a few days ago and have been doing the current line of quests. I chose to be apart of the vampire hunters and am currently on Chasing Echoes. Apparently I can't talk to Serena, at the very start of the quest. Well, this has been happening ever since the quest to return Serena home. For some reason, I cannot talk to her. She follows me around everywhere, but when I try to talk to her, nothing happens. I tried reloading my game to a save before going into the cave, and the same stuff happened. So now I have been using console commands to jump me past talking with Serena in every quest, but it is getting annoying and I was curious if there's a way to fix it. I have been snooping around forums as of late to see if there's a solution, but I haven't found it. All I know is that this character is extremely buggy, and sadly, vital to the quest line.