BLACK MESA

.underground laboratory complex, research facility.

normal day in the facility of underground laboratory complex. nothing seem bad right? now your currently patrolling the lab for a while... then suddenly. EXPLOSION. you went unconscious, after a while, you woke up and everything is on alarm, fire everywhere, people running and dying, creature are now everywhere too. you grab your Glock 17 and ready for something within this facility.

several zombie are blocking your way