wouldn't that be a time stream split? and yeah that would probly the way they go anyway, because if gordan freeman was sent into the test chamber in black mesa to stop "himself" then you would have seen "yourself" in half life. so it does make sense that he would be sent to the combine's timestream/universe so you could make changes that wouldn't affect the "human" timestream/universe directly. but then again these theory's really have not been exactly proven have they. so anything really could happen.

but also what about the technology that obviously teleported the borialis to its current location. what about the story taking us to the combine home world? that would be way more epic in my mind. or it could end in a full story wrap around where at the end of half life 3 it explains the g-man is really gordon freeman.

its also just a game too...lol

well... the thing about "time stream splits" (or whatever you wanna call them) needs some understanding... and there for aren't all ways that fun for new people...

but the more normaly used time travle theory is that you go back in time... and help your self... but the past self aren't to see you... and you aren't doing it cause you "knew" you had to cause else you weouldn't be doing it...

andway... like i said... i haven't even played the old HL to end... and i haven't played HL2 EP2