Entry #12 was posted on August 29, 2009.
It has the description "12."
In total, this clip is 1:00 long.
In this video, Alex is working with one of the actors on his movie Marble Hornets, and they are getting a shot of walking across a field of grass. However, after 29 seconds the color begins to become all distorted, the background fading into darkness while the actors stand out in full color. At the same time, a very minor bout of audio distortion occurs. It fades until the entire background is in silhouette, but when the camerawoman pans back to look at the space from where they came, where someone now stands in the distance, the colors fix themselves and a tall shadowy figure is visible.
Main Observations and Theories
This has to occur very early in filming, because Alex treats the Operator like a regular dude ("Hey, buddy!") instead of a paranormal entity he's being stalked by. If this were to happen later in the timeline, where Alex was more familiar with the Operator, he instead may have freaked out.
Speculation & Analysis
Slender Man seems to be standing in the same spot throughout the entire clip. Alex reassures one of the Marble Hornets crew that he will move soon. Once the actor Tim arrives, Alex is forced to talk to Slender Man to remove him from the set, as they are about to begin filming. ~Morscata12
J responds personally to DavFlamerock about this entry. I believe Dav asked about the abruptness of the entry's end:
"Hello Dav. I have been asked this question numerous times already even though entry 12 has only been up for a few hours now. I should have made it more clear within the entry, I apologize.
Anyway, yes, what happens after that clip is VERY important. Unfortunately, the girl operating the camera at the time stopped recording as Alex walked on screen. There was a little bit of time left on the tape (around 4 or 5 minutes) after this clip, but it's blank. I'm not sure if Alex changed tapes early or not, because I have yet to find another tape that "matches" with this clip. It's frustrating to say the least.
Thank you for the question, I will continue searching.