You have just come in and into your office. Something is off. Then a voice over the intercom tells everyone to evacuate the facility. Black Mesa is under attack. You grab your HEV suit and start running to get out as quickly as possible. (I am young and don't have much time on the mod) (DISCONTINUED)
It is the first map updated, in some parts i could not get it to work so you will have to noclip and there isn't a level transition