ForumI think I know why the G-Man nuked Black Mesa
It makes sense now... the G-Man re-started the nuke that Sheppard defused because G-Man was trying to deny the Combine access to the Black Mesa teleportation technology! He's obviously not an agent for the Combine, otherwise he would have just slipped them the technology, himself.
Also, I think Nihilith was the Xen-exiles' very own Breen-like, post-invasion, corrupted leader who wanted power for himself; that's why he thought of the humans as thieves when they took crystal samples from Xen.
I now have an idea about where the plot is going
1. The G-Man set up the Resonance Cascade deliberately to "bring" the Combine to Earth, but nuked Black Mesa to deny them Earth's most valuable scientific achievement - the teleporation tech that the Combine, themselves, cannot produce. Dr. Breen was most likely in on this, as he knows about Freeman's "Mercenary" work for the highest bidder.
2. Alyx Vance then recovers the "phone number" for the Overwatch homeworld via the escape from the Citadel in City 17.
3. Gordon Freeman recovers something from the Borealis that helps the Resistance access the Combine super-portals.
4. We now repeat the plot of Battlefield Earth where someone uses the bad guys' super-teleporter to take out their homeworld...
Anyone else see this coming?
What I have not seen yet is the G-Man's involvement, or lack of involvement, with Aperture Science. He may have helped "convince them" to accelerate their testing schedule to cause the Borealis incident, and thereby plant the tool which will be used to defeat the Combine 20-40 years later. I do have a strong feeling that those two scientists posing for the picture of the Borealis who also worked at Black Mesa were double-agents and they smuggled the Aperture Science teleportation tech to Black Mesa. Then, after Black Mesa adopted the project, Johnson caught wind of this and accelerated his own testing schedule. Perhaps the G-Man was involved with establishing those two scientists' dual-employment. UserAlexcranson|Alexcranson 2242, April 25, 2011 (UTC)