Hello

I am right at the end of this dlc and it will not let me finish. I get to the think tank and and talk to the brains. After this the game tells you to exit the think tank.Now i do this and where in every fallout dlc there is a slide show at the end well for me there is a black screen and the music. I really dont know whats going on. I have done the talking way and the killing way but still the same. http://www.youtube.com/watch?v=XqDjfnW8ILo&feature=channel_video_title

Thanks

Here are a couple things to try.
Leave the Think Tank before talking to Klen an go back inside.
Load an earlier save, its good to keep a few backup saves incase something goes wrong.
After the screen goes to black, go somewhere else or ten minutes then comeback, sometimes these things resolve themselves if left on there own.
The last thing to try is to reinstall your DLC.