It is the 21st Centaury; you are scientist called Gordon Freeman who has recently been taken on by the Black Mesa Research Facility. Recommended by your former professor, Dr. Kleiner of the 'Massachusetts Institute of Technology'. You have been assigned to work in the Anomalous Materials Laboratory.

You take the transit system from your living quarters to the 'Level 3' laboratories. Upon arrival you get kitted out in your 'Hazardous Environment Suit' ready to perform your daily routine and you're late!
Once you get down to the labs it is apparent that things are a little different. Your two senior colleagues meet you at the entrance to the lab, informing you that today is going to be the just the same as any other day...

You're in the middle of your first experiment when things start to go horribly wrong...

You wake up, heart pounding after what seemed like an explosion. Shell-shocked, you remember strange flashbacks of another world with inhuman creatures. Were they flashbacks?

The test lab is a war zone and it's not safe to stick about too long... You take to your heels not looking back... You soon find many of your colleague's dead or worse, the whole Anomalous Materials level of the Black Mesa is in ruin. You're only chance of survival is to head to the surface...

Once you near the surface things get even worse... Monsters are everywhere and so is the military, trying to clean up the mess you have created. The mess includes you... nothing is allowed to leave the Black Mesa alive.

Sneak your way through the Black Mesa although force is nearly always the only way forward. Get your fellow scientists and security personnel to help you navigate the Black Mesa; you are going to need them!

Fighting your way to freedom is the only option now. What lies ahead is uncertain, it seems that nothing can be worse then your current situation!