No seems to have done this yet so here we go.

/x/philes, we are engaged in some sort of puzzle, perhaps some sort of ARG. Though the trailhead seemed to start last night, the roots of this mystery go back to October 2010.

For reasons that will become apparent, I'll refer to this as the 553312 Mystery from here on.

Here's the thread from last night:
http://chanarchive.org/4chan/x/11643/officers-redacted-and-redacted-arrived-on-scene-at-5533-after-r
eceiving-radio-dispatch-residence-at-33

What we know so far:
The thread from last night contains a few different things. An image (the same one I've posted), three stories, and a post from the Needle Man (more on him later).

The story that captured everyone's attention at first was the story of a man living in an apartment above a chinese restaurant with his wife/girlfriend. The story had a little bit of possibly a ghost story feel to it, or just general creepiness. The story comes to an abrupt ending. Binary code embedded into paragraphs in the story spelled out a link to a video (named 553312) which was downloaded and then subsequently uploaded to Youtube, here:
http://www.youtube.com/watch?v=4nknOkFMXY4

The video depicts what appears to be a young woman in the darkness, illuminated by the light of the camera. The young woman is motionless for the first 2/3ish of the video, then draws what might be an upside down cross in blood and starts laughing manically.

The uploader naturally labeled the video "553312" which brought up this related video:
http://www.youtube.com/watch?v=tx9e3mZs6ls

No connection between the two videos was made initially, but we'll come back to that in a moment.

(continued)