Reckoning
From Halopedia, the Halo wiki
Episode 05 is the fifth of five "episodes" in the Iris campaign. It can be found at http://206.16.223.61/X84xE2/flash/web/index.html. Once the page is loaded, there is a floating and rotating object, with several Forerunner glyphs on it. Three of them link to files to download, and one links to a video that can be played. One of the files, Log5_Transcript.txt, contains the transcript of the video; there is also a text download MB05032 which is a monologue by Mendicant Bias (MB).
The anomalous world is in a perilous location beyond the line. {//} (THE SECRETS IT HOLDS MUST BE PRESERVED) {//} (PLANS WITHIN PLANS WITHIN PLANS) The inhabitants; these unique denizens, must be researched. They may hold answers to our own mysteries. {//} (WHAT IRONY THAT WE DISCOVERED THIS TREASURE, ONLY AT THE END OF THINGS.) {//} (BUT WHAT FORTUNE THAT WE STILL HAD TIME TO SAVE THEM) The thing we built on that world will vouchsafe their lives, {//} (BUT PERHAPS ONE DAY IT WILL MAY BE USED FOR ITS INTENDED PURPOSE NOT) If the plan succeeds, and they are saved, it will be a good world. If the plan fails, {//} (AND THE ADVERSARY SUCCEEDS) it will remain an enigma forever {//} (WITH NO-ONE LEFT TO RECLAIM IT)
This conversation clearly points to the planet Earth as it is located outside the Maginot Line and the inhabitants of Earth. The "thing" mentioned above refers to the gateway to the Ark that, if used right could bring salvation for the humans.
MB05032
You asked me once, what happened to those who vanished?
You asked me, why did we survive where our fathers fell?
You wished to know how we ever let it happen
A scourge that consumed the galaxy
And the cure that was worse than the cancer
You asked me once about my intent
And the spot that would not wash out
I promise you the answers lie in the Ark
Find me there in the dark
For that is where I abide
The final lines of the above can be understood as a nod to the audience, as they seemingly refer to the location of the seventh and final terminal of Halo 3, in which Mendicant Bias addresses the Master Chief directly on the Legendary difficulty.