It is a cutscene from the ark.
At :25 the sentinel says something to Master Chief, something like "Terminus on menosights". I know thats not what he's saying but maybe someone can figure it out? I have a feeling it could be latin perhaps, the "base language" that is referred to in Ghosts of Onyx when a sentinel speaks to one of the SIII soldiers.
It could give some insight to exactly what the sentinels are being deployed for.
I've really been listening to it, I think he is saying "We must keep the prophet (some random word I can't understand) within our sights".
Edited by Maj Williams, 15 August 2008 - 12:19 PM.