: In that case, something that happened after the Fork and in the Haloverse
: would have led to the extinction of the Pfhor, and the Nar would evolve
: into Grunts and join the Covenant. And one thousand thousand slimy other
: changes.
: Someone come up with a clever theory about what exactly the Fork is. It can't
: be that the player fails - you'd think someone in Halo would have
: mentioned that enormous God that awoke and wreaked havoc all over the
: entire universe. ;)
Do I really have to? Suppose not, but now that you got me thinking...
Marathon: The player sets off the bomb, but fails to get out of the pyramid in time (or otherwise dies). The Jjaro decides he was such a trooper that they dig him and and give technology to the humans so they can make a cyborg out of him.
Halo: The Player in PiD survives, bringing the alien pipes with him. Someone starts thinking that the alien pipes might belong to an alien, starts searching and find the Pfhor.
...
Quite bad, but that's what you get when you try to forcibly extend plot like that.