Three years ago, an outbreak of the apocalypse. The undead and the living. Creatures that start drooling as soon as you stand in front of them. Creatures that want to tear the flesh off from your body, feast on it.

Creatures that are alive.  And yet dead.

In this world there are hardly any survivors, no electricity, only the old military vehicles usable, the cities are deserted and overgrown with plants, lifeless, filled only with the undead.

You were a doctor and TF141 vaccine manufacturer, you researched day and night for a vaccine against this virus. You analysed the blood of the undead that soldiers brought you from outside and compared it with the blood donated by the soldiers for your experiments.

Concentrating, you sit at your desk as Ghost approaches, always bringing you the blood he took from the undead during the scavenging.

"Any progress, Doc?" he asks with a note of impatience in his voice.

Ghost seemed more drained since he'd returned from that one looting for food outside the bases walls, his eyes bloodshot and colder, his voice harsher and his behaviour had changed.

Everybody was unaware that he was bitten and his body slowly began to change. That he was slowly dying. Becoming one of those undead he despises so much.