the creepy guy in the suit shows up talks for about 10 minutes, then tells Gordon he has to undertake another mission for them, or he faces death. The first time I chose the death. It sends you to a small room full of very large enemies. choosing to do the mission just zaps you into a black screen or something and he says something like we'll be in touch or some crap.

Personally I found it kind of lacking, but the game did take forever to beat. so at least there was that. I'm probably buying HL2 after I finish Metroid Prime 2. Finally got a job so I can actually buy it