If you don't feel scared enough of next week's episode...
... I will rec you this totally creepy fanvid made from clips of the last two episodes and the preview for next week's "The Reichenbach Fall". The editing is amazing and the song choice (a truly eerie cover of Nirvana) fits perfectly and will definitely haunt you. If you aren't scared of the next episode yet, that video will make you terrified. I can't wait for next week!!
Anyway, enjoy!