AR speaks again, and has a new avatar

[Sir Topham Hat]

The Cortana Letters pertained to the Marathon universe didn't they?

[shamanistcrage]

or Halo 1. but you were close.

everyone thought they were about a new marathon game. but they got halo.

[Maimbot 9000]

No, you're right. The letters were sent to the Marathon's Story page and seemed to hint, rather heavily, that they were related to a new Marathon game.

Later, Bungie backed off the connections and have kind of flip-flopped on just how canon the letters actually are. Cortana uses the same T.S. Eliot quote in the letters and in the Halo 3 announcement trailer, for instance. But in general I think it's safe to say the letters represent some alternate Halo story from early in the development process. There's no telling how much changed from the time of those letters, to now.

[Lichtonatus]

sterilizing makes me think ar is getting completely killed

Or that the being wants to sterilize us. Which is a bad thing on more than one level.

Maybe this new being wants to sterilize Earth, just in case (of a new flood attack). Although from the way AR reacted towards him, I get the feeling this new character isn't one of the good guys

[Sir Topham Hat]

One of the interviews I read told us that as for right now the only pieces of the Cortana Letters that are to be considered canon at this point are the lines used by Cortana in the E306 vid.

[Lichtonatus]

Was that the interview that said about how the Covenant have a library of Forerunner symbols?

I've read that one. Topham's right. they're pretty much entirely non-canonical. Just pretend the only things Cortana has ever said have been in Halo, halo 2, the books, and the trailers.