They say you don't know what you've got until it's gone, and that saying has never been more true than during a zombie apocalypse. Days after the outbreak of a fungus which turns humans into grotesque, zombie-like creatures, Maya watches her parents get mauled to death by the Infected. Left alone with her little sister, she takes her father's gun and they battle through the crowds of Infected and people desperately running for their lives. When they finally reach the edge of the city they are surprised by a military soldier who is ordered by his superior to kill them, and despite Maya's pleas, aims his gun and shoots. Maya thinks on her feet and tries her hardest to save her sister, but unfortunately she fails. All she can do is look on as the last person she loves bleeds out in her arms. Five years later, not long after her eighteenth birthday, Maya and her partner Daniel are offered a deal. All they had to do was smuggle something out of the city to a group known as the 'Fireflies', then they would be paid in weapons which they are in desperate need of. Maya is used to smuggling and is convinced by Daniel to go through with the job in the belief that it would be simple and over in a couple of days, but it turns out to be much more complicated than she expected. A lot more complicated.