I was going to the the Vault manager or leader or something, I forgot.
And when I couldn't help the Tunnel Snakes' leader's mom from being eaten by rad scorpions because the place was such a damn maze, I killed him with a baseball bat to get him to shut up.
And then I killed the Overlord guy.
And then I killed pretty much anyone I could before I left. Which is to say, everyone.
And then I saved the people of Fallout by defusing their bomb, and they chased my out because apparently that's not enough to forgive rampant and indiscriminate kelptomania.
And then I was forced to flee, weak, injured, and tired to Rivet City, but I had no credits.
Then I died.
This is what happened during the only time I ever played Fallout 3. Wish I could do it again...