“You are one of the last surviving rebels in a war-torn city after a prolonged combat against the Combine during the Uprising. The main Citadel has been destroyed giving the Resistance a high ground in the battle while leaving the Combine forces disorganised without proper communications.
Because of this as well as the rebels’ persistent resistance the losing Combine had decided to use their last resort, the headcrab shell bombardment, consequently abandoning the plans of regaining control over that area and instead causing a zombie outbreak. This counter measure has caused almost the whole population of the city to turn into zombies including a considerable number of Combine Soldiers, as well. Right now there are still some small isolated Combine squads remaining in the region.
Since the shelling, you have been staying alone in an abandoned and half destroyed house for a short time. Though at this moment, having no other survivors to assist you and the zombies closing in, you have decided that it’s finally time to try and escape from the zombie filled city and find a new and better place to live in. You grab your only firearm, the shotgun, with the little ammo you have left and set forth through the hazards on the streets.”